I could be waaaay wrong. But my understanding of what it means to be primal is about not eating the processed, sugary foods with a shelf life and increasing your fat intake, not so much being picky-picky about which animal source your protein comes from. Eat like a cavewoman. She would just be eating like a caveman who lived near water without livestock other than her prized chicken. If she eats butter, even better!
Mark does an "Is this Primal?" article. Look at hemp hearts or chia seeds to see what he says about them. Protein in those babies! She can soak/sprout lentils to eliminate some of the anti-nutrients.
She does not need to be 100% Primal to reap benefits. There is a lot of talk about being 80/20 to allow for circumstance and plain old enjoyment. Perhaps her 20% could focus on her favorite protein containing beans/lentils, etc.
Over time she just might feel awesome! Over time she just might change her mind on trying to add more animal protein or she might not. But, being a fish eating/egg eating vegetarian she'll be just fine as long as she commits to eating this protein daily.
good luck to her and to you!