My LO is also 1+ years old and I started to gradually do a transition by introducing fresh milk at least once a day during her meal times. I think that your idea of giving her 2 feeds of formula milk and 1 feed of fresh milk will be a good start.
Yes, over the weekend when we’re out, we give formula in the morning and fresh milk for the other 2 feeds on top of his breakfast, lunch and dinner :)