I really like pureed celeriac/Celery Root. Steam or boil it, then mash/puree with a hint of cream & butter. Beats the pants off regular old mashed potatoes.
Also, try using nut/oat/hemp milks as a basis for the smoothies you'll inevitably make, as they'll up her protein intake and taste better than regular milk. I'm an avid believer in soy protein powder in my berry/banana/hazelnut butter smoothies.
Also, did nobody mention mushy peas?
Good luck, and good on ya.