>My question is, could a girl be so heartless to come back to a man just for the sake of the security even if she doesn’t love him?

Yes

Now that being said, perhaps she is genuinely remorseful for her mistakes. You could tell.her exactly what the issues were, and so.long as she's willing ro work in fixing them you'll.g8be her another chance, but that not going to start with her moving back in, that's 6-12 months away.