Developmental - Yes. Between 6-9 mths they start getting antsy about strangers being in the room, whether their own parents are present or not. This is a result of them being able to recognise differences in faces. Between 9 and 12 months they start being more concerned about mum or dad leaving, and not necessarily so worried about the4 stranger being there, as long as mum or dad is there.
A lot of your DDs reaction will be based on yours. If you are anxious, she will be using "social referencing" where she picks up on all of your cues. So if you're nervously watching her every time your mum is nearby, she picks up on this and becomes nervous herself.

Tips for getting ready for the wedding:
- Spending time with your mum is a great idea. Keep it up
- When you're just around the house, try to be as far away from her as you can. Some 10 month old don't want you to be more than a metre away; try to encourage her independence as much as you can, as it will help her to develop confidence in her self.
- Leave her with your mum. Prepare her for the initial event, then say a fast goodbye (Fast! is the key) and go, just for an hour. If your mum can't distract her out of it, you might need some more prep. But more than likely, she'll calm down within 15 minutes.

Good luck!