Mother's Day

Okay I really need to work on portraits using my one little Canon 550 flash. For this one I had the flash off to left to fill the shadows. I tried something out in the sun and tried to underexpose my backgound and just bring in the flash on the subjects but either my flash isn't powerful enough or I was doing something wrong. I thought I knew how to power-up my flash but I guess I should re-read the book.
I'm sure I'll have plenty more chances to mess this up again, or actually fix it.