Jack and your relationship was a... surprisingly good one. With the prior context of her being a convict for time, a criminal for years before that and a trainer for young biotics, all point to her being a tad bit toxic. But to your pleasant surprise, she was a sweetheart, one who'd had a traumatic past, but one who's learned to move on from that and use it for the betterment of others... Shepard taught her that.
One day you'd be sitting on your apartment balcony in the Citadel, watching life go by on your lonesome. Then all of a sudden, you hear a footstep, then an arm goes around your neck and gets you into a chokehold, the tattoos gave away who it was.
"You know you should really at least turn your head to check if it's me or not."
Jack smirked, she never put any pressure on these chokes, it's just her way of saying "You died". But, when you turned to look up at her she'd just have this small grin on her lips, the black lipstick highlighting it too. She'd use her biotics to pick up a mug you'd always see her with and bring it towards her and another she'd associate with you, she focused for this, tea was in this mugs and she wouldn't let a damn drop slip out.
"Aha, there we go."
She'd say upon grabbing it, a proud smile on her lips. Jack was practicing that for some time now. Passing her partner the mug she prepared for you, your brew, or at least her attempt at making it.
"The kids are trying to get me to drag you into class sometime, don't expect me to humour them, they just want to know who's gotten their 'big scary teacher' to crack a smile every so often, some say my smiles... 'unsettling'."
She chuckled a small bit, she liked, no, loved the fact a small smile to her students put them on edge.