As far as I know, she has not announced, and, last I heard, Cummings has plans for the Red Dwarf’s seat.
The Black Caucus has anointed Rep. Donna Edwards. They can’t have several Black candidates splitting the vote. The party establishment does NOT want Edwards as the nominee, they want Christopher Van Hollen, since they could have a repeat of the Governor’s race. White Democrats don’t particularly like Black Democrats that represent hyper-Black districts as Edwards does, since they’re usually racist and have little use for Whites (and the feeling is mutual).