Kya's BG has definitely been coming down over the past few days and she went too low last night but I'm not sure taking her all the way back to 1u is the right move right now. You were shooting 2.5u on pretty low pre-shots, and during the night cycles the last few days as well as the day cycle of the 31st she may have been going lower than you are aware of so right now.
First of all I would NEVER give insulin without first checking to see that BG is high enough to safely shoot. Second, I would make sure to get at least one mid cycle test in for all cycles but if not possible then err on the side of caution with dosing and third, I would be extremely cautious about shooting pre-shots in the 90s. Novolin can hit hard and fast and for that reason, your aim should be to get Kya into high green (90's) to low blue range during the cycle so shooting at that range is unsafe and even more so if you cannot monitor the cycle closely.
There are a lot of unknowns about what Kya is doing right now. That said I'm not sure dropping all the way back to 1u is the right move but it's difficult to know what the dose should be to get her into good numbers without risking her going too low.
I think if you can monitor her tonight, and PMPS is 200 or more, you could try 2u and see what she does. Ultimately it's up to you and if you feel more comfortable taking her back to 1u that is fine but I still wouldn't give insulin if BG is low at pre-shot and get mid cycle tests whenever you can. I realize it's hard to do on day cycles when one is working but even grabbing an extra test an hour after shot on the way out the door or as soon as you come home will help fill in the gaps in the picture. And definitely get a test every night before bed to see if she is dropping quickly so you can intervene early to prevent lows like last night.