I would make sure you have the locksmith there on day one and lock the place down.

You guys change whole lock during new lease or Re-Keying of the lock.

(give or take).Make sure you also factor in property management fees (even if doing it yourself), lawn care, snow removal, locksmithing after tenant move outs, landscaping and common area cleaning.  

Re-key charge for initial rekeying7.

Send a locksmith or whatever, change the lock and charge them for it.

Since she was pregnant and her husband was out–of–state, I sent a locksmith to the door to let her in.

I looked into this, but I couldn't find a good solution.I have simple (no bluetooth, no wi-fi, no smarts) locks with keyboard/code at home, for the convenience of not dealing with a key, but they run out of battery quite often and we never had the need to upgrade for something "smarter".For rentals, we use the key ones with smart re-key system (5min to rekey them). 

You will be left with rekeying, part of the cost of a cleaning crew and the wear and tear such as little touch ups.Vacancies: Just a tip here. 

Other than that, you can invest a about $20 in a set of metal locksmith stamps. 

How much notice do I need to give her before having a locksmith change the locks?