This sums up what you said.

(Ephesians 2:8-10 NIV) For it is by grace you have been saved, through faith--and this not from yourselves, it is the gift of God-- {9} not by works, so that no one can boast. {10} For we are God's workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do.

God gives all believers spiritual gifts. We should seek to serve in ways that we're good at and passionate about. And of course we should do the things that are necessary but not necessarily pleasant. The church building still needs a janitor. Ideally the people who work in the children's ministry will be those who are passionate about working with children and they're good at it.