Complex sentence: FFS is a very powerful set of procedures but there are limits; for example: a wide jaw can be feminized by surgical narrowing but it may not be physically possible to narrow a very wide jaw enough to make it fully female.
Split into simpler sentences: FFS is a very powerful set of procedures, but there are limits. For example, a wide jaw can be feminized by surgical narrowing but it may not be physically possible to narrow a very wide jaw enough to make it fully female.