Some lovely ideas here!
I’ve bought upmarket handcreams from Space NK before. You’re always washing your hands and they get dry.
Yes to a nice dressing gown from somewhere like Toast, with pockets and made from 100% natural fibres, I was hotter and sweatier than normal when nursing so synthetic fabrics were uncomfortable and you are always short of hands so pockets are a boon.
Another good one is a highly rated thermal mug with a very secure lid and small closable drinking spout/hole. Hot drinks are dangerous around babies and toddlers and I remember the endless cold cups of tea from that time.
Personally I’d avoid vouchers for anything that involves her leaving the baby, such as dinner for two or spas. However well intentioned, she may not want to spend hours apart from her baby for many months, particularly if breast feeding, so the kind gift could end up feeling more like a pressure than a treat. I’ve also read new mothers moaning that grannies desperate for “alone time” with their small, baby grandchildren, have resorted to giving such things for their daughter/ DIL’s birthday or wedding anniversary after having been told that she isn’t ready to leave her baby yet, in the hope of strong arming or guilting them into leaving their babies with them and going out! I wouldn’t want to risk being lumped in with that lot.
Personally, anyone who had turned up bearing nice chocolates for me post-parturition would have been greeted like the Messiah.