Development Question

Hey all,

No pictures right now, sorry! I'm at work on a lunch break. But I thought it would be a perfect opportunity to make a quick post to ask some questions to anyone out there that may have any info. Time again where I'm at a transition with these little guys, and would LOVE any help :)

So, so far Wesley and L are doing great. As you can see from my previous post, Wesley is really developing into a little sweetheart. I'm seriously so in love with him.

Wesley has always been about a week behind L in development, probably due from the first rejections from Rosie and also being the runt of the litter. But, I worry about how fast they're both growing.

L has always looked huge next to Wesley, and each time I go in and hang out with them... I swear L has grown even more.
But, Wesley seems to be a little quicker in the intelligence department. L seems...... well.... kind of dumb.
Part of the reason why I say that, is because he'll be 5 weeks old on Monday and he still doesn't walk. AT ALL. He sort of shuffles his body low to the ground and rolls places (with his giant rolly-polly belly that he has... --which I will get pictures of soon!), but no walking. Wesley doesn't walk either, but he is definitely sitting up now, and has very apparent strength in his front legs. Where L still lies slumped around. He spends 75% of his time lying on his side or back.
At first, I was thinking that it was because we give Wesley WAY more attention than we do to L, and we work with Wesley in an almost "physiotherapy" session, where we make sure he walks to us to get his bottle (so that he gains strength)... but L doesn't have to go far from Rosie to just get a slurp from her. Should we just continue to leave it and allow the development to continue? Or should they really be walking fully by now?

The next thing is the eating. So, they both have some decent teeth coming in. I know that 4 weeks is when they say the weaning should begin. Since Rosie is there, what do you think? Should I let her handle L? Or should I take over? Any tips on the best ways you've all found weaning should go? I've gradually been letting Wesley taste Rosie's wet kitten food off my finger before he demands his bottle... Next I think we're going to mix powdered formula + water + chicken human baby food(or wet kitten food) and see if we can get him to start getting interested in a plate of it... BUT, my concern again above is... if they're not walking.... should I wait until they can fully stand and walk on their own before trying this?
What kind of time in between feedings should I be following after this 4th week? We've finally merged Wesley to go between 5-8 hours (hurray for sleep through the night!!!) - which seems to be working fine for him. He gets 4 feedings on the weekday, generally: 6am - 12:30pm - 5:30pm - 10:30pm, give or take an hour here and there. He's still only eating 1-2 tablespoons of formula though... (more often 1 than two)... which is worrysome. But, he is still pretty small. L is bit over a pound now, Wesley still dangles behind at about 14 ounces. Hoping the weaning process will help him get some weight on... but he looks healthy to me. Anyone know if this is good enough?

Same thing with the litterbox... We're still stimulating Wesley (though I think Rosie does it sometimes for him too), but we're doing it while his paws are in the box so he can relate the scent to going. Haven't found any traces from either kitten in the box... again, should I try leaving this to Rosie with L? And again with the, should I wait til they can walk there themselves? I've found L behind the litterbox, sleeping, a bunch of times... but, that's about it.

Ok... hum... I think that's it. Thanks in advance for any suggestions! Pictures soon :)