Is this a scam, or even scamola?

My wife is selling home school books and this is the conversation:

So it looks like she'll send us a paper check (via Pony Express?) for the items. What could go wrong?  

She also offers an electronic payment from Wells Fargo. No thank you on that front. 

If its Zelle its safe. 

There is actually an electronic payment option out of online banking. It's called Zelle. https://www.zellepay.com/?utm_source=google&utm_medium=cpc&utm_campaign=862090716&utm_term=zelle&&gclid=CjwKCAiAjNjgBRAgEiwAGLlf2gMvUWAeqSLa-YW55i6ezc6bBWFMYkVF0quvHgH6HXbxJ7kq-OzqFhoCdqcQAvD_BwE

Wf uses zelle. I use wf. Is safe. 

I would just ask for a USPS Money Order.

Zelle is pretty cool.  Used it several times now.  Just need a cell phone number and for the other party to be signed up too.  

Everything she said is legit. Whether or not she is is a different story but I, personally, see no reason not to have her send the check. 

My in-laws have sent us a few checks like that and be warned, they come unmarked and look like junk mail. 

Thanks all