That sounds great! If she is already familiar with the acclimating instructions, I’m sure everything will go smoothly on her end once the seahorses arrive.
Tell her to try ordering the Piscine Energetics Mysis relicta from Premium Aquatics. I normally obtain my PE frozen Mysis from Premium Aquatics because they offer it online in small quantities, and they offer it graded for size (when they have it in stock, you can obtain either small Piscine Energetics Mysis relicta or the usual king-sized PE Mysis relicta).
She can order it online from Premium Aquatics (see link below).
Click here: Frozen Foods: Premium Aquatics
If Premium Aquatics is out of the PE Mysis relicta, which happens at certain times of year, your next best bet is to contact Piscine Energetics and obtain a list of the retail outlets that carry their Mysis relicta. Depending on where you live, you may be able to obtain the PE Mysis relicta from a local fish store in your area, and it’s possible that a pet store near Yakima may carry it:
Click here: Mysis Relicta — Natural fish food,for finicky saltwater and freshwater fish, by Piscine Energetics
Best of luck relocating your seahorses, Donna!