
Fortunately, unlike the I curse, M is probably one of the more common first initials out there. Mark, Marcus, Mason, Malcolm, Marvin, Melvin, Miguel, Mateo, etc. Miles too but I'm not sure it'll ever be chosen since it is also a unit of measurement, but could certainly lead to some funny advisory puns.
For Beryl and Helene, which are practically guaranteed, Brenda and Heather are my personal picks.