[Maria isn't very sure she believes that Chrollo cares about Heather. from how he spoke, Maria wasn't sure he would care about anybody else but those he deemed important. certainly not anybody from outside his universe, it seemed. Maria knows it's not good to judge from a first impression but she has. Chrollo didn't do anything to change her mind and she didn't think she'd left much of an impression on him either.

but here he was.]

I wouldn't want you dead either, Vincent. I mean, again, anyway. [she tries to joke, thinking he would appreciate that. he doesn't like sentimentality.] So we'll do what we will. And I'll also look out for you in my own way.

[she did ask people to help him and that was for his sake as well as their sake. to keep him safe.]