Do you have a Lush in your area? Might not be a bad idea to check it out if you do.

Checkout Lush!

Some things I like:

• face masks
• bath bombs (Lush is great for this)
• lip scrubs
• manicures and doing my nails (I like to soak my hands and use cuticle cutters and pushers to clean up the nails, nail clippers and files, etc. to shape and clean up the nail, then I usually do a typical varnish, but the equipment to do gel nails would be nice if she's into that).
• I like to use scented candles when taking baths (I love Frostbeard's Reading at the Cafe candle, which smells like chocolate pastries)
• epsom salts are also great for baths, and there are quite a variety of these now (as well as magnesium bath bombs)
• a basin to put hot water and epsom salts in for soaking the feet can be really nice, too (helps with pedicures to soak the feet, too)
• I've heard good things about those paraffin wax baths, but I don't personally use them at home
• if you are into it, you could get some massage oil and offer to give a massage

A lot of things like eye creams can be sorta expensive and if she doesn't have a go-to for a daily routine already, it might be a way to treat her by leveling up or giving her extra skin care products she might want normally but goes without (but I can't help but think this would require some conversation to know what she would want exactly - I don't know how crucial it is that the gifts are a surprise).

Get an electric paraffin wax bath for hands. They're like $40 or less and are reusable as long as the wax remains clean. You dip your hands into the melted wax and then peel it off a few minutes later and your hands feel amazing. It's also great in the winter time when your hands get dry and cold .