Yes, I worry about that too, expecially with my youngest daughter who I see a family therapist with. I am not sure she is attached to me or to anyone, either securely or insecurely. I worry about that. I think she is attached to our cats. My other daughter and I do have an attachment/connection. I think I am realizing that it is not all the parent's fault when a secure attachment doesn't occur. There can be a lot of external influences on the relationship that the parent is not in control of. Through therapy, I think my daughter and I are seeing some benefits.

I have been wondering a bit about what secure attachment and insecure attachment mean. Is this right:
secure = you are confident the other person loves and cares for you, and you do not doubt the relationship and worry the other person will withdraw, reject, or abandon you
insecure = you are always doubting the other person's investment in the relationship and worrying that they will withdraw, reject, or abandon you

If that is it, it can give me some insights to view my marriage relationship through the lens of attachment. I was never securely attached with my H, because he blocked me at every turn. I tried and tried and he wouldn't permit it. As a result, I had a lot of insecurity about the relationship and this has carried over to the rest of my life, making me feel unworthy of love, distrusting a person's intentions, and doubting that someone would accept my love. I have a lot of damage to undo from the marriage. I think the most healing thing for this is successful relationships. My relationship with my therapist has been healing in that way. It gives me the experience of connection and attachment so that my brain cells remember what that feels like. It's like (re-)learning to ride a bike with training wheels.