[adpiucf]

I think as long as moms are properly vetted, told expectations, and held to them, that things should be ok. It is up to the chapter to preserve ritual and setting some type of written standards and roles for the moms is probably a good idea if your chapter doesn't already do that. If you are concerned about membership selection being compromised, discuss this with the chapter leadership and maybe the moms will be dismissed during certain times and/or given notice that they are not permitted in certain areas of the house in order to preserve order.

ETA: At my undergrad, we didn't utilize non member moms, only alumnae, but our house mother, who was not a member, was discreet and respectful and knew when she could/could not be in a certain area where there was ritual. Good luck!!! I think it is great you have moms who can be involved and help with behind the scenes set up and assistance!