Lily powered up into Juliet rarely. Not never - certainly not never - but by now, the frequency could definitely be classified as 'rarely'.
It was halfway because she didn't take easily to the enhanced ability it granted her, yes. But even besides that, it was also halfway because she saw no need to put herself in danger, and wearing a senshi uniform certainly put her in danger: she might not have been assaulted often as Juliet, but it was still considerably more often than usually happened as Lily.
Outside of the time she'd been kidnapped for apparently no particular reason. It had been a mass kidnapping, after all. Destiny City was a strange place! That kind of thing happened sometimes.
Perhaps if she had been more comfortable as Juliet, as making Juliet into more than just an echo of herself through the funhouse mirror with the most minor of warps, she would have been taken with most of her Court to somewhere far away - but she was not, and as such, she had not been taken with them.
It was a good thing, really. She would have accepted anything that uncanny Queen had told her, had she been involved; as it was she barely knew she'd missed anything at all, and as such didn't feel any particular way about it. Not that this aspect of things was a particular shocker. In general, Lily - as herself or as Juliet - didn't feel any particular way about the vast majority of things: anything that pulled out a true and strong emotional response was an abnormality, and typically a negative one. She wasn't given to strong responses. Or to responses in general. She was, through and through, a thoroughly mild girl.
Cumulatively, though, what all of that meant was that she touched the full-length mirror in her bedroom, ready to mirrorwalk somewhere further away; and it pulled her in, in a different way than normal, like it was clinging to her and chaining her - and that wasn't how it was supposed to feel. She knew how mirrorwalking felt (or was supposed to feel), most of the time, even if she didn't do it often. It felt like - it felt better than this. This was something unpleasantly foreign.
Not that there was anything she could do about it, even if she'd had the idea to do anything. So she just let it happen to and at her.
When the wall half-parted and let her out behind Euporie, she took one step forward, barely aware of where she was - and then, of course, she noticed and looked around with a sort of baffled hesitation. Was that a little girl? Maybe not so little, but still certainly young; younger than Juliet, though she herself fell into that awkward realm of anywhere from fifteen to twenty-five.
Not that it bothered her. Most things didn't.
For example, this entire situation did not bother her, although it was very slightly discomforting. Given another fifteen minutes or another series of strange, unexpected, unpleasant experiences to follow up that warped mirrorwalking, it would likely tip over into officially being designated within her head as 'bothersome'.