Your missus may need a frame with a smaller wheels size, says, 650c, as 700c will be too big for her body proportion.
It limited your choice of frame sadly, but there are decent frame out there (as well as complete bike) that's design for 650c wheels, such as the IRO Mark V HD, it fit a 5'3 person as well as a 5'7 on a 700c.
Your missus may need a frame with a smaller wheels size, says, 650c, as 700c will be too big for her body proportion.
It limited your choice of frame sadly, but there are decent frame out there (as well as complete bike) that's design for 650c wheels, such as the IRO Mark V HD, it fit a 5'3 person as well as a 5'7 on a 700c.