I was started on Novomix 30 and BS came down but was all over the place with big peaks and troughs.
2 months later I changed to Humalog 25 Mix and evertyhing has evened out. I won't go into details but this change over was almost accidental.
I was also given rapid acting lispro pen for 'sick days' so I stuck them in the fridge and forgot them. At recent hospital appointment the nurse told me to use the rapid acting at mealtimes for extra control. I've been doing this for a couple weeks and it seems pretty good so far.
I am still honeymooning though so your daughter may be in a different situation.