I have 2 boys who have/had disordered speech (as part of their autism). Ds2 (4) still has help from a SALT.
Like your dd, ds2's spoken language is much better than his ability to understand what is said to him. He has been seeing a SALT since he was 2yrs-old.
I'm not an expert so obviously can't tell you anything specific about what would help your dd but can tell you how our SALT has been helping ds2.
The first thing was to go back to the beginning with language and teach individual nouns. We had lots of very simple pictures of things like house, doll, teddy, cup, plate etc. You can play matching games and lotto games with them to make it more interesting. We also used simple toys like dolls, dolls houses, bears and tea-sets. It feels really strange at first because it feels as though you're somehow babying your child as you've heard them say much more. It really does help though to build up vocabulary.
Once my ds was doing well with nouns we moved on to simple verbs using similar methods as for nouns. Lots of simple pictures of people or animals walking, eating, climbing, swimming etc. Again it's about building up understanding.
It also helps if you break down your day-to-day language into simple language, eg instead of "Do you want to go to the park, Jane?" you say "Jane go park?" You will feel really silly and self-conscious to start with but again it really can help.