Cousin getting too close

So my husband had shared his fear with me this week that my cousin is getting too close. His fear is that she wants my life he is worried and keeps having nightmares she steals our children (ages 2 and 6 weeks old.)

So as of lately my cousin who I had been extremely close with most of my life prior to my husband's and I marriage (prior to the last 9 years.) Have been spending lots of time together. She even hand made our boys elaborate gifts for birthdays and just because. She also helped me throw a giant birthday party. My husband keeps asking me what her angle is?

She is always saying things like "I'm living my dream through you." "We always said we live by eachother and do everything together." This is making my husband uncomfortable. This cousin and her husband have been so sweet lately and love our kids. She and I have had rough spots in our relationship however it is nice to have a village of love for our kids.

Does anyone else have people without children "living vicariously through you" and it not be weird? Like I so enjoy her company and help. The only time it got weird was a night she wanted to come over and I told her no as I needed sleep. She threw a massive fit. She then very fastly apologized.

Has anyone that is family actually tried to take someone's kid? Feel like that is just stuff for movies.