I had the same problem with Jasper.
But once I had him sitting and staying everything else got much easier.
I would just hold a treat above his head to focus him in my direction, then say sit and wait. Even if his attention strayed, the moment he finally sat he got the treat and a "good boy".
Rinsed and repeated this untill he knew the score and then focused on having him stay by first having him sit, then saying "stay" with a treat on the floor next to him. If he moved before I told him, i'd swipe the treat ...rinse and repeat.
From there things got much easier.
Been with us now for about 5 weeks... absolutely no training before hand. He now sits, stays, lays down, rolls over, kisses, gives paw, stands up.... goin well
Good luck.
oh, if she's attentive to you when getting her food ready then use that. Make her sit before each time you feed her. At least that'll get her assosiated with the command.