Troubled youth pestering me

Theres a young woman in my area who hangs out at the bus stop near my house. She blasts music and sits there vaping and will take to people who go by (like myself). She's asked my child's dad for money to get vapes and also other people. She sees me with my kid or with my dog and has stated trying to be my friend. The other day she told me about her home life which she wasn't happy about. I could see she'd been crying and her exact words were "my family make me feel like killing myself". I felt real bad and asked her if she wants to come in for a cup of tea. So she did, told me how awful everything was and her back story. When it approached bath and bed time I told her she has to go. She did. But then she came back later, and the following day. I didn't answer the door. Then she followed me and my son to the park today. I spoke to her at the bus stop yesterday and she gave me an update on her home life (social services and police involved)... When she followed us to the park I felt there wasn't much I could do. It's a public area. She was being "nice" enough and not.being aggressive or violent so I thought I'd just be nice. It was awkward. She was giggling and joking with my son who was going down the slide. But she's mentioned some really messed up things like how her lover is gonna come.and see her and how "he's got a girlfriend but he likes me". She's not a woman's woman. She told my partner that she's a pron star... She told me that her parents took her phone and bank card. If she was 20 and they were really stealing from her would she not move out? She asked what I was doing and I was explaining all the tasks I had to do to try and let her know I was busy. Then put my son in his pushchair to go and she said she'll walk us down... Then when she's walking alongside she says to my son "I could play with you when mummy's doing laundry"... I just started walking faster and faster and went home. She went back to the busstop but now I'm worried and not sure how to handle the situation.