Would it be wrong to just send a gift and call it a day?

I was in town the about a month or two ago and I ran into my daughter and her step mother out shopping. I had told my daughter I was flying in because I had to handle business related things at the company, so I wasn't going to see her until a little bit later that day. Either way, like I said I ran into her and her step mom (a little earlier than expected) and the woman and I started to talk briefly. Then the conversation somehow got into the fact that she's pregnant and she wants me to come to her baby shower. At the time my daughter was standing right next to her while she invited me and they both seemed to be excited. But in all honesty I don't want to go to the shower at all. I don't live near them ( I live on the other side of the country, but I am there frequently because of my husbands company) so it's not a problem of me getting there, I just don't feel like being around my daughters fathers side of the family. I mean there really isn't any hard feelings there between the family and I (I was never married to her father) but I feel a little awkward there and a bit much of an intruder. I do have a pretty open friendship with her, I just never thought she would invite me to her party like on the spot like that . I specifically went shopping with my daughter the other day to pick up some items for the new baby and the shower is supposed to be this weekend but now I feel like only sending the gifts and a card with well wishes instead. Will that make me look distasteful? I was going to bake a pie to send over there for the party as well.