Loved the Angelcare bath seat - before we got this, it was a two man job with a tiny wriggly baby and clueless parents. Once I had this, I could do it myself much more confidently.
Recommend Cheeky Wipes or a cheaper/homemade equivalent (cut up old towel and a Tupperware would do). SO much better for cleaning off poo than disposable baby wipes, plus cheaper in the long run and better for the environment. Can later use them for getting food off hands and faces (also way better than normal wipes), wiping down the high chair, wiping food splashes off clothes, cleaning faces/behind ears etc in the bath...
I had a very cheap, second hand vibrating bouncy chair which was brilliant. And also a second hand gym with lights and music to lie the baby down on, for stimulation (and to drink a cup of tea). No need to pay loads for these things as many people use them for a couple of months then sell them on in good condition for much less.
Infacol is good to have on standby in case of colic.
Lots of sheets for the cot/crib. If she's getting a Moses basket or crib now then a cot or cot bed later, she could just get the bigger size flat sheets and you can tuck them under the smaller size bed. Saves a bit of money if needed.
Baby sleeping bags! A must. Preferably the GroBag brand. Expensive new (eBay or TK Maxx are often a bit cheaper) but if you look on Facebook marketplace or eBay or whatever then you could get some second hand bargains. You'd need a few, and in different tog ratings.