Her name is Barbara Millicent Roberts and she lives in Willow, Wisconsin USA. She was born on March 09, 1959 to her parents George and Margaret Roberts, Skipper and Tutti are her sisters and Todd is Tutti's twin.  Best friends are Midge Hadley and boyfriend Ken Carson. 

Barbie doll markings are found on the right side buttock, neck rims are not marked, any other markings on the backside, inside of arms and inside thigh were used by the manufacture for assembly and do not date the doll.  The trademark date is the first date of patent or copyright in the country of issue.  Note:  Barbie ponytail dolls 1 to 4 have the same doll mark Barbie ™, ponytail dolls 5 to 6 are marked Barbie ® 

850 #1 Barbie Ponytail doll

early part of 1959 

Only about 350,000 of the first Barbie dolls were produced, the Barbie doll is made of heavy vinyl plastic, partially solid body now probably quite white, blonde or brunette saran ponytail hair (Blonde's out number Brunettes 3:1), curly bangs, metal cylinders in legs, symmetrical holes in feet bottoms that fit on to a black pedestal stand, right foot marked: JAPAN, white irises, side glancing eyes, pointy ^ ^ eyebrows like lightening bolts,  some of the early Barbie dolls have hand painted faces, others were stenciled, red painted closed mouth, No marking on back of head, one piece black and white zebra striped swimsuit, black open toe heeled shoes with holes on the bottom for stand, white sunglasses with blue lenses, gold tone hoop earrings, black pedestal stand with prongs, cardboard box has ™ in the marking and a pink booklet with only Barbie on the cover. 

Number One Barbie 1959 marking: Barbie ™, Pats. Pend. ,© MCMLVIII, by, Mattel, Inc.  

#1 Barbie feet with hollow tubes,

right foot marked: JAPAN

Values for number 1 Barbie dolls with the holes on feet bottoms and lightening bolt eye brows are usually in the thousands of dollars, the better the condition of the doll, having all her original accessories will command the highest value.

850 Barbie Ponytail doll

35th anniversary 1994

Reproduction 1959 Barbie doll has honey blonde or dark brunette soft shiny polyester ponytail hair with loosely curled bangs, pointed eyebrows, heavy black lids, painted white iris eyes, big red closed mouth, hollow plastic flesh colored body that won't turn white, dolls have holes in the feet but no tubes in the legs, no Japan mark on bottom of foot and there is a mold line on the front and back of the legs.  Came dressed in her reproduction black and white zebra striped swimsuit that has plastic straps to help keep the swimsuit in place (the original did not have these), black open toe heels, white sunglasses with blue lenses, gold tone hoop earrings, clear stand, reproduction of the #1 box and graphics.  Mattel sold a ton of these reproduced Barbie's and many can regularly be found in online auctions for a modest amount, usually under $20.  1994 Barbie on back marking:

Barbie ™

Pats. Pend.

© MCMLVIII

by

Mattel

Inc.

MALAYSIA

850 #2 Barbie Ponytail doll later part of 1959

Same as Barbie doll number one, but no holes in feet or cylinders in legs, new disc pedestal stand with black wire that fits under the dolls arms, same black and white stripe swimsuit, white sunglasses with blue lenses, black open toe heeled shoes, some came with new pearl earrings, pedestal stand, box has new ® in the trademark, and a Barbie booklet

Doll mark: Barbie ™ Pats. Pend. © MCMLVIII by Mattel Inc.

850 #3 Barbie Ponytail doll 1960

Similar to Barbie number two doll, with new blue irises, new softer curve to eyebrows some dolls with brown or blue eyeliner, same black and white stripe swimsuit, white sunglasses with blue lenses, black open toe heeled shoes, some came with new pearl earrings, pedestal stand, cardboard box, and a Barbie booklet.

Doll mark:  Barbie ™ Pats. Pend. © MCMLVIII by Mattel Inc. 

This number two Barbie doll has also been reproduced by Mattel and the neck rim should have a marking.

850 #4 Barbie Ponytail doll 1960

New type of plastic retains flesh color, came in blue eyeliner only, rest same as the number three doll including she wore a black and white swimsuit and same accessories were included.

Doll mark: Barbie ™ Pats. Pend. © MCMLVIII by Mattel Inc.

NOTE:  This is the last early Barbie with the Barbie ™ in the marking.  1961 and newer the mark changed to Barbie ®.

850 #5  Barbie Ponytail doll 1961

New hard hollow torso, new hair color of titian (auburn), plus blonde and brunette, a little firmer texture to the hair, some have the old soft hair and some have a combination, the number five doll face may have the greasy, shiny face syndrome, some do not, came wearing a black and white striped swimsuit, new black all wire stand, pink booklet with Barbie and Ken on cover, rest same as the number four doll and accessories - see new marking. 

Doll mark: Barbie ® Pats. Pend. © MCMLVIII by Mattel Inc.

This is the 1st year that a ponytail Barbie came with Titian, red or auburn hair color:

850 Barbie Bubblecut doll 1961

New bubblecut hairstyle, new titian (red or auburn) hair color, blonde, brownette (this is the lighter brown or sable color only sold at Sears), and brunette almost black color, rest same as 5 and 6 ponytail. Lip and nail colors vary from red to pale bubblegum pink.  The Brownette hair color is rarer than the other hair colors and therefore commands a higher value, she wore a black and white striped swimsuit in 1961 only just like the earlier ponytails, same accessories as prior ponytail Barbie dolls. 

Doll mark: Barbie ® Pats. Pend. © MCMLVIII by Mattel Inc.

850 Barbie Bubblecut doll 1962

New red one piece helenca swimsuit, various lip and nail colors, new undated box (see box in ponytail 1962), rest same as the 1961 bubblecut.

850 Barbie Bubblecut doll 1963

Slightly taller body, rest same as 1962, new markings of Midge and Barbie. 

New doll mark: Midge T. M. © 1962 Barbie ® © 1958 by Mattel, Inc.

850 Barbie Bubblecut doll 1964-1965

Same as 1963 bubblecut doll marking with the word "patented" added to the last line of marking. 

Doll mark:  Midge T. M. © 1962 Barbie ® © 1958 by Mattel, Inc.  Patented

850 #6 Barbie Ponytail doll, box dated 1962

#6 - Ponytail Barbie, new hard curly bangs, new red one piece helenca swimsuit. New undated box with new graphics that show both bubble-cuts and ponytail dolls.  Same marking and accessories as prior doll: 

Doll mark: Barbie ® Pats. Pend. © MCMLVIII by Mattel Inc.

850 #7 Barbie Ponytail doll 1963 - titian hair color

#7 - Ponytail Barbie dolls 1963 - New doll mark:  Midge T. M. © 1962 Barbie ® © 1958 by Mattel, Inc. just like the bubblecut dolls in 1963. The box graphics are the same as prior doll, but box is now dated © 1962.  Same accessories as prior doll.

850 #8 Barbie Ponytail doll 1964-1965

#8 - Same as the 1963 doll marking with the word "patented" added to the last line of the marking. 

Doll mark: Midge T. M. © 1962 Barbie ® © 1958 by Mattel, Inc. Patented