Hello:
I have been type one for almost 55 years.
If your daughter is feeling weak and shaky her level is too low and should be treated.
We are all different and experience “lows” differently.
Personally what I have found over the years is that I do not feel weak or shaky anymore so I also have to monitor more often than I used to.
I would never go to bed with a reading of 4. Not ever!
Maybe her bedtime snack could be increased in the amount of carbs to avoid the lows at bedtime.
Ray
I am so sorry about your loss. Hugs.
I’m sorry for your loss. I believe that we grow as a parents, and as a human beings, as we learn to trust our own instincts and and our children’s as well. You’re advocating for her and also helping her become independent. Keep up the good work!
An anecdotal story: when I started reading this thread, I noticed I was feeling low (shaky, increased heart rate, weak) and my CGM read 87… but it was 87 and dropping fast. The symptoms came on fast and I knew it wasn’t your average 87 so I treated the low. Within 20 minutes I had dropped to 59 before it began to come back up (currently at 100). I’m glad I trusted my instincts! 
This will be a shocker, but this is my rule for my boys provided to me by their endo. The highest they want my boys BG is 150. Our doctor advised not to put them down for sleep any less than 150. However, my 13 year old I have to put him.down at no less than 200 bc if I do come morning he’s gonna be close to a danger zone of too low (less than 70). If I wake up in the middle of the night to check my boys and they have 4 or more hours until they are due up and less than 100, I give them 15g of juice. I’d rather them be high than low. My husband who is also T1 dropped too low in his sleep last year, resulting in a major seziure that the convulsions caused 3 broken vertebrae in his back. I cannot in good conscious let my boys sleep knowing they are at the lower end of a BG.