Hard to tell from the picture and I'm not a vet, but to me it looks more like a nasty shallow scrape than a serious laceration requiring stitches. I'd probably try my best to keep it clean to prevent infection, wouldn't let her lick it because it would keep reopening the wound and wouldn't let it heal, and watch it closely just in case there should be some changes for the worse as then it would definitely require a vet visit. Fingers crossed, hoping it heals soon.