Toy Poodle Feeding, Coat

Question
Dear Doctor,

I have two toy poodles, a 6-month old girl and a 3-month old boy.

My first question is about the girl, who's been with me for about 4 months. She ate well during the first few weeks after she came to me. Then I took her to the vet trip with me for her second shots, and she puked all day after we came back home, which I think was due to the dewormer pill the vet gave her. A couple days after that, when I took her to my friend's house, she had a little my friend's dog food there and the second day she had bad diarrhea. Ever since then, she lost her interest in her dog food. I tried a couple different brands, Iams, Scient Diet, Ekunauba, she would eat only the first couple days when I gave her new food, then she would quit. So I stoped giving her treats a few weeks ago, and also because of the new boy's coming, she's doing better with her dry food, but still not enough I think. She's underweight and I can very easily feel her ribs under her very thin skin, and I'm trying to give her some canned food every afternoon. Should I do so? Could you give me some advise on feeding her dry food?

Second question is in recent a few days, I noticed there is some red color/thing in the girl's stool. But everything else looks fine with her, and her stool is solid. My boy friend thinks it could be the red lint from her blanket, but the boy's stool does not have the red color at all. They are laying in the blanket together all the time. For long time, I think the girl's digestion system is having some minor problem, because she pukes at night every once a while. Sometimes I know because she ate some grass outside, and sometimes just no reason at all. And she's easy to get nervous.

The last question is about the puppies' coat. When I first got the girl, her coat is curly and fluffy. After a couple months, her coat tangled a lot even I tried to brush her every other night. So I clipped her hair with a #3 blade, which now I know was too short. But after that, her hair is growing slowly now, and not that curly any more, and very thin. I heard two different opinions so far about grooming. First the groomer at PetsMart told me not to trim puppies' hair until they are 6 months old, otherwise their coat will look "wierd" after they are grown. Second, puppies' hair should be trimmed to bold for 3 times before they are fully grown, and that will make their coat pretty later. Is any of these correct? Was I wrong to trim my girl's coat when she was about 5-months old?

Thank you very much for your time.
Cecile

Answer
As for the eating, I would get with the vet.  It really doesn't sound like she has been right since the last visit.  Healthy dogs will nearly always eat all they need and more.  If she is sick, she may not eat no matter what you try.  

I think clipping her was a mistake.  However, I doubt any lasting damage was done, although if she already had her summer coat coming in, she may not be right until her winter coat comes in.