just purchased the fs5, (in the post!) having FCP 7 will this edit native ok or is there a work around
thanks

No it won't edit it natively!

If you also purchase the Sony XDCAM Firmware Pack for the FS5 you MIGHT be able to edit with that - but the FS5 records XAVC-L otherwise. So you are going to have to transcode the footage (I will let someone else suggest good software for this as I never need to transcode anything I edit).

I really think you need to look at updating your NLE - if nothing else you'll realise just how much faster you can edit with modern NLEs on a decent Mac for editing.

What about trying out the free version of Resolve if money is tight? FCPX is not that expensive either.

I think you'll love the FS5. Have fun and hope this helps.

. . . or is there a work around


As Andy says, the "workaround" is to migrate to a modern, faster, better, NLE.
Not just for XAVC campatibility but also for all the other improvements that will allow you to work faster and better. Time is money.
Unless you are just a hobbyist there is no reason for a professional to be hainging onto FCP7.