However, there is something to be said for building relationships with others you trust – who can bravely and wholly stand in for you.

When my photographer friend was pregnant, she had a cut off point for when she would book the last wedding before her anticipated due date. But as that last wedding approached, she was great with child and simply couldn’t do it.
She asked another photographer friend to shoot for her – fulfilling her commitment to the couple. I think that is perfectly reasonable.
I’m sure they were disappointed – but still delighted with the other photographer’s work.

If it’s something big to you – it’s okay.
You just need to know who you trust ahead of time.