Both of my ladies probably ignore Luna, tbh, but I think she's absolutely adorable and I love your PB choice for her.
Mafalda and Alecto probably do know each other, though! I think it's likely that Alecto is aware that Mafalda is a supporter, but that Mafalda preferred her work with the Ministry over taking action herself. Passive support, basically. So Alecto can take that as she will!