You can have a relationship with her again but it will be more work than when you guys were younger. She is inviting you to be a part of her family life. From there, you could attend her kids ballgames with her, be like an aunt. She probably doesn't get much time to herself alone, so it's not a slam to you. I wish I had done more of this myself, is why I'm saying it to you now. It's how you build a life.