Aaugugh, everybody run!! Vance has FLEEEEEES!!!
Oh, fees. Right. Sorry.
Back when I was thinking about doing the pet portraiture I came up with a pricelist which is very similar to the prices you have here. I based mine on both other pet photographers (which there weren't many to go by) and a few regular portrait photographers, trying to be somewhere in the middle to slightly above middle price range. I haven't done any of this type of photography so haven't been able to test these prices, but feel pretty confident that they are in line with what people would be willing to pay. So I'm not the best person to answer this question (not from an experience standpoint at least), but I think you are in the ballpark. The only thing I would add is a 16x20 price and maybe a 20x24, which you will be asked for from time to time (especially if it is a full family portrait), and perhaps keep in the back of your mind canvas prints.
My thoughts on pricing are, as long as you aren't waaaay out of touch (which might just scare people away from the start), you can always lower your prices or offer "limited time" discounts if you find people complain or are hesitant to buy. It's easy to go lower, it's hard to go higher. But that doesn't mean it's ok to knowingly start too high.