I designed Kids with Heart clip art collection for Valentine's Day but I think it would also work for Mother's Day too. The balloons are big enough for you to customize and add your own text.
Includes...4 kiddos, 5 balloons, 1 candy box, and 1 flower bouquet. 11 high resolution png (transparent backgrounds) images. Commercial use welcome. $3
<<<Update>>> I just added Kids with Heart holding a banner that you can add your own text to. Similar to the one below but with no words so that you can add your own.
I'm also giving one with the words Happy Valentine's Day as a freebie! Click the image below to get yours.