There’s online evidence that she didn’t cover her hair k’halacha
I’ve seen that there’s a Nshei Chabad newsletter who interviewed her Sheitel Macher of the last 20 years of her life.
Now, it’s not good evidence, as she’s a Lubavitcher and could be covering up. But there’s no reason for the Rebbetzin to have gotten her Shaitels from outside Lubavitch. So while there’s no smoking gun that she wore a Shaitel, there’s no reason to assume she didn’t.
For the record, Rebbetzin Nechama Dina (the Frierdiker Rebbe’s Rebbetzin) wore a Shaitel Lav Davka with a hat, Rebbetzin Shterna Sarah wore a Shaitel Lav Davka with a hat, and we don’t have pictures of any of the earlier Rebbetzins.
and I’ve heard that she wore pants.
After a quick search, the only source of that I was able to find online was FailedMessiah (and in the comment section, a few people asked for a source. They didn’t get any response).
I hope you don’t get your information from that rag.