My mother is flying solo from TPE-NRT-IAH.
I was able to use UA GPU to upgrade to business class for the NRT-IAH leg.
TPE-NRT leg is serviced by ANA.
Given that she is flying economy from TPE-NRT, can she check in at ANA business-class counter in TPE? Can she access Star Alliance Lounge in TPE (I think there is only Eva lounge?)

Thanks.