Daughter at First Ultrasound?

It looks like we might have to bring our 4 year old with us tomorrow to our first ultrasound. We haven’t told her (or anyone) yet because we were waiting for this ultrasound to make sure there’s a heartbeat, etc. If everything is good we will announce on Easter to her and then everyone else as well. I’m afraid if we have to bring her tomorrow she’ll tell people afterwards which we don’t want. Has anyone been in this situation? What did you do to distract at the appointment? I’m hoping she won’t catch on, but she’s had several people pregnant recently and she always says she wants mommy to be pregnant too. I’m thinking she will catch on so what have you done in this situation?