I think it’s fine to do this, unless it takes over your life.
I’ve watched shows such as Toddlers and Tiaras, and get the impression that for some, their only extracurricular activity is these pageants. Some people seem to go to these pageants every weekend. It absorbs all of the family free time for such people. It will crowd out other activities your daughter could be involved in.
As long as it doesn’t take over your life, so long as you don’t end up doing this every weekend, your daughter should be fine.
And by all means, if she wants to play soccer, or other activities such as Girl Scouts, have her participate in those activities. Work the pageants around the schedules of other interests she has, rather than having to squeeze in other things around the pageants.
good advice - it’s a nice “mommy and me” activity, but we have other children, older ones, they still like to have some of that time, too :)