This girl keeps texting me, What should i do?

Ok so im 18 and my mate's sister added me on facebook who is 13, i talked to her n she started saying she wanted to go out with me and do stuff and started commenting on my photo's, my mate told me to delete her coz he said she meant trouble so i did n then she took his hone and got my number, this was a while ago, she texts me asking to meet p and stuff, i just said im busy n i told my mate, he got her to delete the number, then few months later, she got my number again but she made up she was someone else and asked to meet up then i told my mate again n he tryed to get her to delete it, now months past until the other day, i got a text saying she was was at a garage just 2 doors away asking me to come out, i asked who it was, she said it was (someone else's name) and kept asking me to meet up with her, should i ring the police coz this is starting to bug me now?