My girls are very social, friendly little things but they wouldn't go near my dad, and to some extent my mum. We don't see them often, but when we do they would cry and scream. I felt bad because I knew Dad just wanted to hold them but I had to respect the girls. We just didn't push it, he would keep his distance and speak to them gently (he was worried they were scared of his deep voice). This has gone on for about a year now, and finally the other week Claudia offered up her packet of biscuits for Dad to open. I think he nearly cried with joy. I think you just have to allow her to do what she is comfortable with and not let them force themselves on her.