It depends...some have come in baby carseats and if the parent doesn't take them out than I don't ask. If they are out or older I interact with them on their level and some just naturally climb into my lap. I like to meet during the day so I don't want them held too much because I want to see how they interact with my current group. In the Fall I had a little girl come with her parents who sat with me throughout the whole interview!! Her parents loved it and said it made them feel good that she took an instant liking to me. unfortunately I didn't end up choosing them and that was a hard one to say no too because they were great!
Last summer my husband did a little yard work for others and I'd go with him to deal with the customers. During a conversation with one couple, it came out that I have a hdc. They had a fairly new baby and she asked for more info and than asked if I wanted to hold her baby and pretty much threw her in my arms lol. It was fine but also a bit strange I thought....I don't think I'd want strangers holding my new baby lol