Bachelorette/pre wedding outings

So future MIL planned a whole day out for us next weekend in celebration of our wedding. I'm not all that close to my family and she doesn't know any of them. In 10 years she might have met them a couple of times, if that.

When planning our outing she didnt invite any of my family , except for my mom. I didn't bring it up to my cousins at all, but I just had 2 of them over and they asked when the bachelorette would be.

Now I feel like maybe I hurt their feelings by not mentioning the outing previously, but mostly I'm just not a very social person to begin with and didnt want to force future MIL to change the plans a week before since I have no clue what she is planning.

I did let them know when they asked future MIL had made plans for us, but we could do something the weekend before the wedding. They seemed to be fine with that, but I'm kinda feeling a bit awkward.

Thoughts? Advice?