I’m not a detective, don’t work for the FBI, etc. so I’m obviously only guessing. I’d see it along the lines of:
They have stated they’re now looking into “things” (obviously covering arses as seemingly ignored the July tip-off from TM Jr)
M apparently received a copy of a letter which may, or may not, have relevance re the accused
Timeline of accusations could (or could not) have relevance
Any investigation should cover numerous aspects, via numerous people/players - covering all bases
So I don’t think it’s beyond the realms of possibility that they’d want to interview her. Not because that’s an immediate assumption that she’s guilty of anything. But because that’s what a thorough investigation should do - build up a complete picture of significant people to try to establish a bigger picture understanding of what the situation is.
M, herself, stated in the press that she’s “known” since 2018 (or 2019!). And supposedly told her father, in writing, she “knew” in 2025. Therefore, surely, if the FBI is conducting a full investigation into TM then they’re going to have questions for people that, supposedly, knew about stuff before this whole thing broke in the press. They’d be remiss NOT to want to ask questions of her.