At the start she was my friend on Facebook and then somehow she got deleted and I then sent her a friend request but I didn't get a positive answer. should I send her another friend request what should I do?
Absolutely not! I know this from experience. I have deleted a guy and he keep friend requesting me and messaging me it was creepy! You obviously aren't as extreme but if she deletes you that means she didn't just want to ignore you on Facebook she just didn't even want to deal with you. There are very few cases where people actually deleted by accident and even if that happened she would have friend requested you or at least accepted your friend request. Stop wasting your time on her, she will just be less interested and maybe creeped out. Just let her go and find someone who appreciates you.
I'm sorry to say this, but I feel like she deleted you purposely. It could be for many reasons, and one may not even be because of you. If she deleted you and didn't accept your friend request, than I suggest that you don't bother with her. Maybe message her and ask her why, but don't bother adding her.
Nope, once is enough. If she said no the first time, she's not saying yes the second time. Plus you'll start to appear clingy (which sounds like it would be true) and you will only annoy her. I'd forget about it.