Despite her lack of romantic experience, Liara still knew that it was an unusual question to have to ask. Her first thought had been to go to Doctor Chakwas; after all, the commander's medical records must contain the information she was looking for. However, after being firmly informed that "It is not my prerogative to disclose personal information about my patients," she needed to consider alternatives.
She thought next about Kaiden since he had been on the Normandy before any of the rest of the team. Tali, though, had let it slip one night that Kaiden was sexually interested in Shepard and that she had rejected him, so Liara felt odd about asking him. The quarian didn't know herself, and if she didn't, Garrus and Wrex probably didn't either. Ashley seemed somewhat stand-offish, and she didn't trust that any answer that Joker gave would be serious, which exhausted the members of the crew she knew well enough to talk to.
She could have tried searching the extranet, but she didn't have a secure connection of her own on the ship, and she didn't want Shepard to think that she was spying on her. (Years later, as the Shadow Broker, she would find recalling that concern quite humorous) Out of other alternatives, she resolved that she would simply ask the Specter. Their relationship might have been just beginning, but surely, this was not too personal an inquiry.
Her next opportunity came shortly after their mission to Tuntau, when the commander visited her small room behind the med-bay.
"Liara. Just thought I'd stop by for a couple of minutes before my shift starts." There was light in Shepard's green eyes as she walked in, and the asari smiled up at her. These talks had become the highlight of her days, and even if she was a little nervous about this one, she still felt the slight giddiness the commander's presence usually brought on.
"It is good to see you. You seem in a pleasant mood."
"Well, we had a good day yesterday. Wrex got his armor back, the pirates got shut down, and I didn't even flip the Mako over."
"I am glad to hear it. There is something that I wanted to ask you while you are here. Since we are beginning to, I mean to say, we agreed that we both felt, that we are…"
"Dating?" Silently, she thanked Shepard for saving her from herself. Liara got so flustered around her sometimes, but the Specter never made her feel more uncomfortable about it than she already was.
"I believe that is the human expression. And since we are dating, I think that perhaps I should know your first name. After all, it is not as if you call me Doctor T'Soni."
Shepard laughed, but there was no mockery in it, only amusement and affection. "God. You're right. It didn't even occur to me. It's Ashara. Ashara Shepard."
Ashara. It rolls easily off the tongue, actually sounding somewhat like asari she thought. Ashara and an asari. She liked that. "It is a very pretty name. Why do you never use it?"
The commander's smile became wistful. "You've probably heard about this already, but when I was 16, the little colony I grew up on was attacked. Batarian slavers came, and…" Shepard paused, the lingering pain of the wound showing through despite her best efforts to mask it. "Anyway, when the Alliance rescue team found me, everyone who'd ever known me as 'Ashara' was dead or gone. I think I just started going by 'Shepard' for a fresh start."
Liara had indeed been aware of the rumors, but hearing them confirmed by the woman she'd come to care about was something entirely different. Tentatively, she reached out a hand to comfort her, letting it rest on the commander's strong shoulder. "I apologize, Shepard. I didn't mean to bring up such an unpleasant memory."
Shepard's smile brightened again, her hand rubbing Liara's arm. "Don't worry about it. You didn't know." The commander got up, and as their touch broke, Liara was surprised by how much she regretted the loss of that little contact. "I'm sorry, but I've gotta go. My shift is starting."
"Of course. I am glad that you came." She forced herself to smile back, but inside, she was worried that her question had driven Shepard away.
And then, just before the commander exited the room, she turned around. "Liara, I think I'd like it if you called me Ashara sometimes."
So, because of the voice acting, nobody can call Shepard by her first name, but I thought it would be interesting if there was an in-setting reason for it as well.