Spaying and neutering can be stressful on everyone, but it does have benefits.
The most obvious benefits are definitely eliminating oops litters, reproductive cancers and hormonal spraying/marking. Other benefits to consider is the fact that once the procedure is done, hormones dissipate… this is like allowing someone to not be in PMS mode 24-7. Hormones make them naturally territorial and defensive, because that’s what mommies need to be in order to defend their nests and babies. Once the hormones die down it takes away the natural stress of securing nesting space and territory to reproduce. That is a major factor when it comes to bonding. Coming from personal experience of having high hormone levels, once you can get them under control you feel so much better and it’s a lot easier to relax and get along with other people.
You could speak with your vet about any concerns you have with the procedure itself. Spays are a big surgery, with risks, but it’s pretty straight forward. Even in the case of the bunnies being in early pregnancy during the procedure (which happens on occasion) it’s still a standard slit and stitch process. Our Tilly was a year old when she got spayed. Since then she’s quickly litter trained, is more trusting, and finds it easier to relax anywhere rather than just in sheltered corners of her cage.
Duncan, our boy, was a stray and about 3 years old when he was neutered… He’s still a territorial bunny, but not as much as before his surgery. He went from trying to dominate all the time, charging and nipping… to now he is learning to trust more and he is a cuddle bunny with Ms. Tilly.
Ultimately it will be up to you whether to spay your girls, but I recommend it from experience. If you can’t afford it now, perhaps making a vet fund will help. You can put aside 5, 10, 20 dollars here and there, until you can afford the spays… and once they are complete it would be good to continue in case of any medical emergencies or even just routine visits that will be needed. I wish you and your furbabies the best.