WHICH SPELLING?

This is the name that we have chosen for our third child and first daughter. Our sons are Axton James and Emilio John. This baby girl's middle name will be Jane. The Isa is pronounced like Isabella. My mom's middle name is Lynn, and Jane is my MIL's middle name. So, I wanted to spell it Isalynn to honor both mothers, but I kind of feel like it's too much and we should just go with Isalyn. We are ABSOLUTELY POSITIVE that this is our daughter's name, we're just in a dilemma over the spelling.