I had my mum the first time, and DH really appreciated someone to support him. This time however everyone (including DH) was 600km away.
With my first bub, MIL was actually the offended one when she asked if she could attend and was told 'no thanks'.
My mum was a little offended when my sister asked me to go with her for her first bub, but she never would have told my sister that.
Geepers that was a ramble, but no I don't think it's that common. She can always be part of doctors/clinic visits, scans etc if you still want to include her....or not - your preg, your decision
I think it really depends on the relationship both you and your DH have with her.