I would definitely take your DD to the wedding seeing its interstate. There is no way you would survive all that time without feeding.
Hoobley - Have someone you trust on call in case your DD needs to be taken home and put to bed. Its going to be a big day for her as well as for you.
We have a wedding photo of me holding my niece and when she was married she is holding my GS. So it can have special memories having babies at weddings