I highly doubt a Mother Superior would also have a secular job in which your male friend would be her subordinate.
I suppose it depends on what the job is. For example, a school that is operated by a religious community or which is attached to a cathedral will often have the abbot or dean as the chairman of the board of governors, which would mean that all employees of the school are subordinate to the abbot or dean. I say abbot or dean because I am mostly familiar with schools that are operated by male religious or a cathedral, but I can think of at least one girls’ school where the head of the female religious community that operated the school was also in overall charge of the school. So if the person concerned is a schoolmaster at a convent school I suppose a mother superior could well be his boss. I imagine that there must also be similar arrangements at hospitals that are operated by a community of nuns. Alternatively, could she not be a religious superior in a regular third order, in which case she could have a secular job, e.g. teacher, nurse, social worker, while also serving as, say, prioress of a community of religious sisters? Do superiors of regular third order communities use the title Reverend Mother?
the only reason he’s deduced that she’s Catholic is because she has Marian statues, rosaries, and books by Catholic authors in her office. Which could just as easily mean she’s Anglican, like you suggested. All he knows is she introduces herself as “reverend”
All of that (Marian devotion, praying the rosary, reading literature by Catholic writers) would sound perfectly normal for a High Church Anglican. You don’t say where you are from, but as you say “other side of the country” I guessing USA or Canada rather than UK. In either case, female Anglo-Catholic clergy with doctoral degrees are not going to be particularly uncommon. It’s also not uncommon for Anglican clergy to be non-stipendiary, meaning that she would probably have a secular job in addition to her clergy job.
“married”, “lesbian”, “ordained”, “bishop”
I’m not sure why all those things have to be in quotation marks as if to suggest that they aren’t real. She may not be considered to be sacramentally married or a validly consecrated bishop in the Catholic Church, but she is surely married according to the laws of California and of the United States of America, and she is presumably also considered to be an ordained bishop in her own Church. I live in England, where Anglicanism is the established religion. I do not feel any need to say, ‘Justin Welby, the “archbishop” of Canterbury, was “consecrated” a “bishop” by the “archbishop” of York, John Sentamu.’ I also do not say, ‘Lord Paddick “married” his “husband”, Petter Belsvik, in Norway in 2009.’ And I’m not sure why ‘lesbian’ goes in quotation marks. Are you suggesting that she isn’t a genuine lesbian or that lesbians don’t really exist?