I have three puppies they were born 25th Feb. All three are thriving, 2 are quite sturdy on their legs, but the 3rd who is much heavier than her siblings is still quite wobbly. I have frightened myself by reading things on the line about wobbly leg syndrome. Do you think it could be because she is much chubbier than the others that her legs aren't strong enough to carry her weight yet. Other than that she is very alert, she feeds well(maybe too well) and is adorable.
You all helped me through a nightmare a few weeks ago, so I thought you were the best people to ask before I really panic and go running to the vet again.

Others may know more, but I would tend not to worry.  If she gets her tummy off the floor (no longer "slithers"), holds her head up well and is alert, the wobbling is probably OK.  At 3.5 weeks puppies are still pretty wobbly in general anyhow,  and I have had some who took longer to get around because they were heavier than their siblings.

Thanks for your reply, it's very reassuring.

http://www.petmd.com/dog/conditions/neurological/c_dg_wobbler_syndrome

Wobblers is known in the Basset Hound (note the breed pictured in this article!) but that's different to a puppy, especially one who is young and has become heavy who isn't strong on his legs.   Sometimes with an overly heavy puppy you see swimmers which again is different to a wobbly puppy, or one with Wobbler Syndrome.

I'd not panic because this is plenty early yet, but to put your mind at rest, it may be worth having your vet take a look - remembering that they all develop at different rates.

Swimmer puppies can be identified by their flat chests, which causes them to have their front legs too far apart. They benefit by having gentle massage, and a rough surface, such as rolled towels, to aid their attempts to get up on their legs. I have known some breeders to use egg trays as a surface for periods of exercise and play. Once up on their legs, they seem to develop normally. I have never heard of a puppy that did not recover, but would have serious doubts about breeding from a dog that had suffered from this condition.