I don't like to pass my babies around. On day 1 of my child development class, my favorite early childhood ed professor told us a story of when her son was born and her favorite professor visited. She asked if he wanted to hold the baby. He declined and told her not to pass her baby around, that it was important for babies to bond with their parents. I always think of that. I really don't know how long that should last, but I just do what feels right.
I took my dd's to a neighbor's house for a playdate for my 5 yo, and the mom wanted to hold my 4 mo., I could tell. I needed help at the moment anyhow because I needed to get myself out of the sling and my coat and take off my boots and all that good stuff, so I asked her to hold her for a minute. This turned into 15 minutes or so, and I found myself "on guard" the whole time and so relieved to get her back. I like this woman a lot, but I don't let go very easily.
When we get to my parents' house, the first thing I do is hand her to my mom. That's different. My mom will give her back as soon as she fusses. With dh's family, I hang on to her because there have been times with my older one where she cried and MIL won't give her back and MIL has "allergies" and often visits with us when her health is questionable, to say the least. If I see that MIL is actually healthy, I'll pass her around as much as she will tolerate, for short visits.
Once my older dd was old enough to walk/crawl and wanted to be on the floor more than held, I knew she could get back to me and was more ready to branch out, so I never minded her visiting with others then. Funny thing is that MIL used to act like she was going to be so shy and that I was doing her a disservice by taking her back as soon as she cried, and my older dd is such a social butterfly at family gatherings. Turns out that my hubby and his siblings used to hide behind MIL at family gatherings according to dh's family, so they can't believe how social my dd is. I just smile and giggle on the inside. I think that if you build that bond and that trust early on, they have an easier time separating later on.
Mom to: Honey (6/04) and Bunny (9/09)