It looks like she's already paying more than the ARV, so I would suggest trying get a bit lower on the asking price and budget at least $10,000 reserves up front for unexpected surprises. 

-if there was an unexpected expense (such as a car repair or family emergency) that the service member didn't have the cash or credit to pay for, we would arrange for a certain military charity to offer a no-interest loan (or sometimes grant) to get him by for a couple months.  

As long as your savings continues to build, preparing for the next purchase and keeping you ready for any unexpected repairs.

The last rehab I did, I budgeted 14k (and I've been doing this for a while), but some unexpected things came up, causing our cost to fly past 20 (I'll calculate the damages next April, it's making money now). 

Also, confirm who handles the HOA-related items, it's not uncommon for PM's to not provide this service and it falling back unexpectedly on the owners.

Turned out all my properties I was under my deductable so that was a unexpected 16K expense thanks to Irma.Two weeks ago I got a notice from my insurance carrier notifying me come October my insurance will no longer be renewed due to lack of documentation that repairs had been made.I called my agent and apparently there has been some mix up on their end. 

Can I fund the unexpected capex items, and can I maintain a reasonable level of tenancy.

It's hard to tell without knowing the exact breakdown of what value you are assigning to each component of these parks. 

The first property you get will have closing costs and need probably several thousand dollars in a "general fund" to fund your advertising, maintenance, unexpected CAPEX, initial vacancy, etc.

The more units, the better chance you'll have of making them succeed and any unexpected vacancy will not be so painful.