Not technically, but other Y spellings have been historically recorded:
Ysabell - 1279
Ysabella - 1207, 1275, 1279, and 1283-84
Ysabelle - 1253
Source:
http://snipurl.com/8x6o
It'd be no surprise to me if
Ysabel was used along with the above forms, even though it wasn't recorded.
Miranda