Activity for Leanne

My fiancé's niece and nephew are coming to our wedding of 25 people. They're 10 and younger and the only ones younger than 15-years-old attending. I was wondering if anyone had any ideas on how to keep them entertained so they won't be so bored...

I'm having a very small and intimate wedding next month and I still don't know I'm going to have any music. I was thinking of a harp, but I'm not sure. I don't know if I want to use a phone and speaker or if there's a way to keep it from being tacky....

I was wondering if anyone had any suggestions about how to have some music for an outdoor wedding. We've been thinking about maybe an harpist, but we don't think $500 is worth what will probably be less than 35 minutes with only 25 people...