When you've made the investment in TYR swimwear and Speedo swim caps, it can be a bit vexing when your young swimmer says that they want to add other activities into their life. If your child wants to skip practice so that they can pursue other interests, or just hang out with friends, what can you do?
You definitely don't want to force your child to swim. Spending time in the pool and racing is a lifelong activity that you want them to love years into the future. Making the final decision to participate in an activity should be up to your swimmer, but try to remind them of the choices that they made.
If at the beginning of the season your swimmer agreed to go to practice on Mondays and Thursdays, hold them to that agreement. A random swim schedule is not good for an athlete's development.
All of this is not to say that your child can't do anything other than swim. Participating in other sports and activities can actually be complementary to swim training. Coordination and balance are both skills that are better developed in other sports. Your child may also enjoy socializing with peers outside of the pool. Getting involved in other activities can have its downsides, though. Your young athlete may not be able to progress as quickly as they'd like to simply because they aren't practicing as much as they could if the other activity did not interfere.
Depending on the age of your child, it may not yet be time for them to specialize in a sport. So let your child have fun! That's the most important part.