Renters asking to break lease early in SF

[Roz Enfield]

Hi Community,

I have some great renters ( a couple and their friend) in San Francisco with a lease through Oct 31. They just emailed that their situation has changed (the couple is pregnant and want to move in with family in Wisconsin and then move to Spain) and they emailed stating that they are pregnant and want to break the lease on July 31.  I'm open to helping them but don't want to be stuck holding the tab and have a few questions.  

1. We're thinking of giving a loose agreement to let them move but that it's contingent on us finding replacements.  How would we phrase that?

2. San Francisco is very "pro-renter". We're not under rent control, it's a new SFR, but realize there are restrictions on landlords collecting rent/back rent. What if we don't agree or give a loose agreement and they just stop paying? Are we out of luck? They have a 3rd roommate who will not be moving out of state.

3. We'd like to cover ourselves in case a prospective renter wants to move on July 1 instead of Aug 1, is there a way we can ask them to agree to leave earlier than July 31 if that happens?

What would you do? Am I missing anything here?

Roz