My changing relationship with my sister

I have decided to let my sister get on with things.  The reality is that she will probably have a million questions and she will need a mother's advice.  I have realised that my position as the childless older sister is going to dictate my relationship with both my sisters' future children. I have to confess that I just can't really face my husband's growing extended family. Moreover, as an infertile woman, it puts me between a rock and a hard place.  If I come on too strong then I am regarded as the desperate childless woman whose clock will soon start ticking and if I completely ignore the situation then I am a hard nosed selfish career woman.  Everybody else will be analyzing what I do.  I won't want to be all huggy kissy over the baby because lets face it, if a childless woman picked up your child, would you not think she was creepy??  I will only approach the child if given permission and I guess I will reluctantly hold it like I did with my SIL's son. It took me a fortnight to meet him and I only briefly held him very tentatively at the end of the visit.  This is the worst aspect of infertility, not being able to have a child is bad enough, but to be constantly judged and having to explain  your every move is a nightmare. The fact that my situation has affected the way that my sisters can tell me what should be extremely happy news is so unfair on them.    I just can't believe I haven't cried yet.