Tenniel’s pictures of Alice are not pictures of Alice Liddell, who had dark hair cut short with straight bangs across her forehead. Carroll sent Tenniel a photograph of Mary Hilton Badcock, another child-friend, recommending that he use her for a model, but whether Tenniel accepted that advice is a matter of dispute. That he did not is strongly suggested by these lines from a letter Carroll wrote sometime after both Alice books had been published…
‘Mr. Tenniel is the only artist, who has drawn for me, who has resolutely refused to use a model, and declared he no more need one than I should need a multiplication table to work a mathematical problem! I venture to think that he was mistaken and that for want of a model, he drew several pictures of ‘Alice’ entirely out of proportion — head decidedly too large and feet decidedly too small.’