How can I clean out my "MobileSync" Application support folder?

My Aunt asked me why she had such low memory left on her computer, she has the low 60 GB hardrive, but when I did some digging I found that under application support the file "MobileSync" has 20.7GB out of the 60GB. I believe this to be a pretty important folder but is there anyway to clean it out to lower the data its taking up.