Something you want, something you need, something to eat and something to read.
That's what our stockings always had!!
At 1, I'd keep it to just a couple of pieces of fruit and maybe a small bag sweets and small bar Cadburys or similar.
Need - like a nice toothbrush, socks, hair bobbins, ....
(As DD was due on Christmas Day, I had a small tub sudocreme, nice Christmas Bib, and a small furry animal toy just in case she arrived on time for a stocking!!!!!!!!!).
Always always had a book!! (And any "kids" at home on Christmas Eve in my parents still get their book, fruit and sweets!!).
Want - things like crayons and a nice colouring book or even a few free printables rolled up, small toy, sheet of stickers? (or too small yet?), a small ball, stuffed animal....
Maybe a decoration for the tree - especially if you would like an heirloom one either for her first Christmas or especially if you'd like to get her one every year that she can have for her own tree when she leaves home. Doesn't necessarily have to be £££, but something different and personalised could be really special.