Ethnicity and RACE are irrelevant to the identity of a Jew.
if she was raised in the Reform community, she really ought to already know the answer to this question and I think you must just be asking this out of your own curiosity and don't wish to offend her by asking things you want to know.
It really does not seem likely that if she was actually practicing or living Reform Judaism that she would be " nervous because she didn't know how her future children will perceived by the Jewish community."
Now..if she was actually never raised in Judaism, even her conversion in infancy could be called into question because she also had an opportunity when she beame the age of bat mitzvah to accept or reject that conversion. Her parents undertook an obligation to raise her in Judaism when they had her converted in infancy. if they did not do their part..she should now do it for herself and either educate herself ( if this is the case that she was not raised in Judaism and not living within the Jewish community ( that might be why she COULD possibly be "nervous" if all she knows about Jews and Judaism are from non Jews instead of any Jewish community where race is irrelevant
so, if this q is legit..it depends upon how she was raised if she is even considered a Jew in Reform ( I think kaganate missed the part about the fact that a conversion done on an infant in Reform is supposed to require the parent to raise the child in Judaism and that at the age of bat mitzvah she can accept or reject the act and formally become a member )
ASK the RABBI
is the best answer..and if this q is legit..It seems to indicate she may not have been raised with Judaism in her home.
Seriously, if a Jew wants to know about something to do with Jews or Judaism, there is little likelihood they're going to repeatedly ask non Jewish friends, or ask their friend to inquire on a forum that is user submitted and has so many antisemitic ranvings, rantings and missionaries answering for Jews with misinformation that I don't personally know any Jew who asks anything about Judaism on any forum that is not exclusively a Jewish forum moderated by respected Jewish educators or Rabbis or who would not first ask Jewish family, friends or a Rabbi.
IF for some reason she would be concerned to be accepted as a Jew according to Orthodox Jewish standards and to have her children so accepted, she would require undergoing conversion to Orthodox Judaism before the children are born
This is more than just a mere formality, it means she would be obligating herself to live and raise her children according to the strict adherence of Jewish law and to customs that are practiced in the Orthodox community to which she will need to affiliate.
I have known a few Jews who first came to Judaism by Reform conversion and then underwent Orthodox conversion later.
I've also knew a man who converted via Orthodox and who sincerely wished to live according to the strict guidelines and did for a long time, but then later joined a Conservative synagogue after he met, fell in love with and married a Conesrvaitve Jewish woman and wanted to sit with his Conservative Jewish wife at services.
The child of any woman who is a Jew according to halalcha ( Jewish law ) is considered a Jew.
Race and ethnicity are irrelevant at all to determine Jewish identity.
The only thing I could think of that could be a concern to her as one whose parents converted her as an infant to Reform , marrying a Reform Jew ...wondering if her children would be considered Jews..would be if her conversion to Reform Judaism was in question!
and ONLY a Rabbi can answer that.
if she was legitimately converted via Reform and her Reform husband and her are only concerned about what Reform thinks..there is no problem
if she wants to be considered a Jew by all movements, she she will seek orthodox conversion but that may not be possible if she will be married to a man who may refuse to live in a home with strict observance of Jewish law and customs.
Orthodox Judaism does not accept Conservative conversions either.
There have been black Jews since before Moses received the Torah at Sinai.
I'm a Reform Jewish mama, child of a father raised Orthodox,Mom raised Reform
I'm a former Jewish educator . in my extended family there are Jews of several "races" and many ethnicities.