I love my Kuya's kids so much that I feel my heart so wide open with concern for their safety and wellbeing. It's typical of Filipino families to be involved with everyone's lives, but is there a line of meddling I shouldn't cross?

Definitely, there is always a borderline even with family members who already have their own family. It's normal for us to have so much love for our nieces,nephews,grandchildren. However, at the end of the day, whether we like it or not, we still have to give due respect to the parents of the child. My sister is in the same shoes as yours. She loves my kids so much and I love her too. But I always remind her about the limitations as I don't want her also to get in the way if ever I'd have a conflict with my husband.