My answer is not designed to be scaremongering, but I think that your arrangements are fraught with risks:
1: Is your friend a 'cat' person, or used to having/looking after pets?
2: Does your moggy have a cat flap? If yes, it can be a good thing from an access point of view, however, it could attract other moggies through it which could be problematic for yours. If not, is your friend prepared to 'muck out' the dirt tray every day?
3: Catteries are only of any use simply because your moggie would be locked away and fed daily, but it would not like it, I can assure you.
4: You must seriously consider what you'd do if the worst scenario happened, i.e. if anything terrible happened to your moggie during your absence - would you hold your friend accountable, and if so, would it result in litigation, or loss of a friendship, or both?
5: Will your friend have your permission to, if necessary, take your moggie to the vet if anything untoward happens to it? And if so, would you expect her to pay for any treatment etc?
There is no easy solution to leaving a beloved pet behind when you go away. It's a chance you take. I sincerely hope it works out for you.