I trust your judgement. If you think it'd help, go ahead, but I'd still be careful about keeping them at arm's length.

[ He's cool with Kasumi. Kind of. Shepard trusts her, that's good enough for him, not to mention they did just kind of all go through hell together and get out, that does wonders for bonding. ]

She told me she's willing to stay out of the way, but with her skills, she'd be better at exploring the ship than anyone else.

And she managed to keep out of trouble well enough, with Shepard.

[ THOUGH SHEPARD ISN'T AROUND NOW :( So he does sound a little uncertain. ]