Invitation Dilemma

We just received an invitation to a Jack & Jill baby shower, addressed to Mr. & Mrs. X. for my DH's college friend. It's being hosted by the MTB's sister, whom I don't know. I'm not sure it's a surprise (I don't think so, as it's at their house on a Saturday afternoon.) But the RSVP is the sister. Anyway, as the invite was addressed only to Mr. and Mrs., is it safe to assume the babies are not invited? I'm not sure I want to ask the hostess, as if they are not I don't want to put her on the spot, but if they are not invited, I doubt we'll be able to find a sitter (as my DH's brother is getting married the day before and I'm using a round robin of my family on that day).

This is becoming an issue these days. We were invited to a Communion, addressed to Mr. & Mrs. for my DH's cousin and I lined up a sitter, RSVP'd and his aunt says 'I can't wait to see the twins'. I said I thought they weren't invited and she says of course they are, I just figured you'd know. But we've received invites to X Family, and I've been sure.

I don't want to be rude and assume -- what should I do?

Does the hostess know you have a baby??? It may have been an oversight. I would ask the hostess... its her job to answer the ?'s. If you get a sitter and kids are welcome then people will ask 'where is so and so?' and if you bring the baby and kids arent invited people may say 'OMG they brought a baby' But since its a baby shower I am guessing kids are welcome. But just ask to be sure.

I would ask ... I think weddings are more formal, so more people are particular with having kids there or not. It could be an oversight or it could be intentional, but it doesn't hurt to ask so you know!