Hmmmmm, pretty broad category. Do you know if she likes a fully enclosed slipper or a scuff? Myself I like something with a covered heel because my feet are always cold. Other people run hot like a friend of mine who only wears scuffs.
If I were you I'd take a look at Zappos. You can see all the different styles side-by-side and read the reviews for pros/cons and fit. Here is a search narrowing women's slippers down to those priced $50 and under:
https://www.zappos.com/women-slipper...HiAgQBAhgN.zso
Be sure and take into account if she wants to wear socks with them which might put her up a half size.
I like the look of these. My cold feet would be snug as bugs in a rug!
Tundra Boots Abigail
https://m.media-amazon.com/images/I/...5L._SX480_.jpg
I also have to give a shout out for
Acorn products - just love them! Their polar fleece
Versafit socks are the bomb!
Backcountry has them on sale right now.
This Moc gets great reviews and you can get the Versafit sock that matches them (both come in other colors).
https://m.media-amazon.com/images/I/...DL._SX480_.jpg
http://cdn2.backcountrygear.com/medi...colatedots.jpg
This pattern is cute - kinda like having leopard paws:
https://m.media-amazon.com/images/I/...aL._SX480_.jpg
Edit/Add: A great thing about using Zappos for a purchase like this is their 365 day free return policy. They will even ship new items out before receiving your return! Give them a call, tell them what you need to exchange for and they will ship it right out to you. Of course you have to give them a CC # just in case you fail to return the original item but it's still a great deal for those of us who hate to wait. I WANT IT NOW!
Hmmmmm, pretty broad category. Do you know if she likes a fully enclosed slipper or a scuff? Myself I like something with a covered heel because my feet are always cold. Other people run hot like a friend of mine who only wears scuffs.