2 new 5-wk Kittens, 1 not eating well

Question:
 Just brought home a pair of female littermates last Fri. A bit younger than I wanted (but you can't always choose these things as they we getting the boot from the rest of the litter). One is about 2x larger & has a great appetite; but #2 eats much less & for a shorter duration. At first I chalked it up to being pushed out the bowl by her larger sister, but now I'm getting concerned there may be a medical problem? Both appear healthy & were checked out by a vet. Am I just being a nervous father? My previous cat was almost 18 when we had to put him to sleep last Jan due to bone cancer - been a long time since I've dealt with kittens & then for just one! TIA, FDONLC (former dog owner now likes cats)
Answer:
 Hello FDONLC, Welcome to this wondeful website!!! Bravo to you for taking in these wee furbabies into your heart and home. I love dogs too, also horses, and of course, CATS!!! LOL Since you stated both kits have been vet checked; I would not be too concerned. I have a friend who raises Persians and Manx, and she just emailed me a picture of two little girl littermates ~~~ also five weeks old. One girl is normal size and the littermate is the tiniest thing I have ever seen in my life. Honest. But, both have been vet checked and nothing abnormal to worry about. You also stated both are eating well. As long as they are eating and drinking, they should be just fine. If you think the tiny one needs more nourishment, the following is an old stand by recipe for "Kitten Glop" that is used by many cat breeders. Best of luck and keep us posted on your furbabies. Have you named them....aside from number 1 and number 2. haha. Just kidding. KITTEN GLOP. for hand rearing and weaning kittens Good for building up Moms and ill cats too 1 can evaporated or goats milk.(2 Cups) 1 sachet gelatine(2 teaspoons) dissolved in 1 can (2 cups) boiling water. 2 tablespoons real mayonnaise. 2 egg yolks 2 tablespoons plain yoghurt 1 teaspoon Honey 1 capsule acidopholus. Mix well and store in fridge. It will set like jelly. Take out as much as is needed and warm in microwave - it will turn to milk again. It can be frozen in ice cube trays enabling one to use a small amount at a time. I am sorry you lost your precious cat of so many years. I know from experience it is hard to say goodbye to an old friend like that. These kittens will keep you busy!!! Take care. Welcome again!!!!
Answer:
 Thanks Kichwa for your encouragement and the great recipe for "KITTEN GLOP"! I'll pick up the ingredients I don't have on my next run to the store. The little one (Lucy) *is* definitely eating and drinking (as evidenced by the litter box) so I guess she's just on the small side. The difference in size really is amazing as her sister (Grace) looks like a sumo wrestler by comparison! Appreciate the warm welcome! And the kind words for my departed buddy Calvin (I still get choked up when I try to talk about him - imagine that...over a cat!) ;) FDONLC