At 8 months, your cat is essentially a teenager, add in those hormones, and even though she's sweet and nice, she's still a crazy case. Spaying calms them, and as she matures, her 'purrrsonality' will come out. She'll grow to enjoy being petted and loved on. Our female cat Monkeys was nearly feral up until she was spayed. It took about 6 months for her to calm afterwards (as the hormones worked fully out of her system) but she became much more tolerant of us (and our other cats) As a matter of fact, she bonded after being spayed, to our 12 year old tuxedo cat, and they have been snuggle buddies ever since. Definitely get her spayed, asap. It will make hers, and your lives better.
If the personality thing doesn't sway you, unaltered female cats can spray urine. Nasty habit to break if you don't get her spayed if she starts.