It's been a long time and I'd forgotten what can be done using the CU CO-OP shared branch network.
So being curious, I called MY CU today to see what can be done to access MY CU accounts from a foreign CU location. I was told...
--I can access any of my EXISTING accounts at MY CU from a foreign CU location.
--I can NOT open any new accounts at MY CU from a foreign CU location.
So your daughter would not have been able to use a local/foreign CU to open a Roth IRA savings account at HER CU.
Option, if more convenient to do so.... But now that she has a Roth IRA savings account at HER CU, she should be able to use a local/foreign CU to make contributions to it for 2019. (And then use the money in HER CU Roth IRA savings account to buy additional equity shares in her Fidelity Roth IRA.)
So for day-to-day convenience, she should be able to use a local/foreign CU that is part of the CU CO-OP shared branch network, as if it were a local branch of HER CU.
Disclosure. When I've traveled and gotten cash from a foreign CU, their security procedures bordered on the annoying when they required me to prove my identity before letting me get cash from MY CU. I suppose that is understandable.
(Added) I remember being so annoyed once by all of the identification I was required to produce before withdrawing MY money, that I asked if an identity thief would be required to produce just as much information... and was told, "No, because it's not his account."
So the first few times your daughter accesses HER CU accounts from a local/foreign CU, she should expect something similar and to answer many questions to prove her identity, before access is granted.