Sorry calling someone a bridezilla, demanding, dictating, etc from what's written, it's all much ado about nothing; IDK why most default to some horrid situation, I don't immediately think like that. Sometimes things really are out of hand but it's nowhere near as frequent as people around this board discuss it IMO.
And if OP doesn't feel like contacting the bride or her daughter for clarification guess she can decline or go with what's written on the website/invite. Honestly I'm not even certain why the OP was invited, it almost sounds like her daughter wants her there for familiarity (maybe she doesn't know many IDK) I guess but for most weddings you don't invite the bridemaid's mother to a shower when that person has no relationship with the bride and the OP isn't her daughter's plus 1 as that's her husband.