I believe subject to transactions, done CORRECTLY, between KNOWLEDGABLE participants, with FULL DISCLOSURE, are typically successful transactions that have benefits for both sides.  

Personally, if your market tends toward the former condition (better/normal appreciation) I think it's a fairly safe deal looking at the long term, assuming infrastructure around you continues to support the idea of renting it.

Does anyone have experience with that kind of transaction?

You can find some diamonds in the rough don't get me wrong but if you aren't experienced enough to see red flags in the property/ transaction they can be costly. 4.

While I’ve completed six transactions, I now primarily use my license for referrals rather than active practice.

If you want low, safe returns that are truly passive, invest in the stock market.  

She could refer people to you for various aspects of the real estate transaction, but you should not locked in to working with her.  

Being a transactional RE broker in my first 15 to 20 years nights and weekends were a must to be a top earner.

Additionally, when comparing whether to build a single family portfolio or a comparable multi-family portfolio, you should also keep in mind the transactional costs involved.

As others have said, no REI is totally passive, if you find the right group with all venders in place, the investors that I work with find it can be a pleasant transaction.