Need knitting advice: gauge way off!

I'm going to a baby shower on Sunday and I wanted to knit something fast before then. I decided on socks and a hat. But when the hat pattern is written for a gauge of around 4.5 or 5 stitches per inch (and the hat is meant to fit an older baby), mine is coming out at 7 stitches per inch. I'm afraid it will be too small, but I don't want to take it all out and start over unless I need to. There are 80 stitches, so I figure the hat will be approximately 11.5 inches circumference. I found a website that says newborn's heads are about 13-14 inches around, but hats should be 1 to 1.5 inches smaller since they stretch. Should I risk it?? What do you think? Any advice?

Thanks,
Dana