how to keep unspayed cat happy?

last october someone dumped two cats at my workplace and i decided to take them in cause we knew who dumped them and knew the kitties were neglected in their lives . i believe one is the mother and the other one is her daughter, miss mother is completely happy with us and is thriving but her daughter doesn’t seem happy.

we have an appointment for her to be spayed next month but does anyone have any advice on how to at least keep her content until then? (we live in a remote community and we couldn’t travel during winter which is why it’s taken so long to get an appointment) we also have unfixed male cats (separated ofc) around 150m away from our door.

she meows 24/7 which isn’t a bug during the day but at night it shoots my nerves cause of how loud she is and i can’t sleep. i play with her for quite some time before bed until she seems bored/done with her toys and i’ve also switched their feeding schedule so they’re fuller at night. she only wants attention from me or my fiancé when she’s "excited" (that one pose unspayed kitties do) and doesn’t really want love any other time so i don’t think her meowing is attention seeking.

it almost seems like she’s in a perpetual heat and i feel terrible every time she cries, i can hear her while i work so customers definitely can too. is the only solution waiting for her appointment or is there anything i can do in the meantime to help her out? her momma doesn’t have any of the same behaviours either. !!!rehoming isn’t on the table at all!!!! and im only looking for advice to help my kitty in the meantime. she may be a bug but it’s not her fault and i love her to death!!!!