I've never had good luck with the whelping pudding, my girls don't like it. If your momma doesn't eat it you could try my "recipe" for a few days. It's 1 can of goat's milk (from the baking aisle of Walmart), 1 can of water, 1 egg yolk, 1 tablespoon Karo syrup, pinch salt substitute and 1-2 tablespoon plain or vanilla yogurt. My momma's love this and it helps them get calcium, nutrition, and fluids all in one. You can also mix this goat's milk formula with canned food to help "spark" their appetite. Sometimes you have to put the food into the whelping area if the momma won't leave the puppies to eat. If I need to supplement puppies I use the same goat's milk recipe with either less yogurt or none and it works well as a puppy formula too.
Make sure your girl's whelping area is warm but not too hot because if it's too hot the puppies won't nurse well and will get dehydrated plus the mom won't lay with the puppies. You will know it's a nice temp in the area if the puppies are laying close together and mom is laying with them. If the puppies are all spread out it's too warm. I keep my area 77-80 degrees but having no drafts is very important. Also keep her in a quiet area, especially since this is her first litter. It will help her relax and feel secure, if momma is worried or uptight she may pace around or pick up her puppies and move them around potentially injuring one or cause her to not produce enough milk because of stress.
Weighing puppies is very important to make sure they are gaining weight and doing well. I use a postal scale because it weighs in grams which is more accurate than ounces - especially for newborns. You will know they are getting enough milk when they lay quiet, crying puppies who are crawling around their box are either too cold or hungry. I weigh mine twice a day for the first week then daily until 2 weeks old. After 2 weeks old I weigh them every week. I even have a weight chart I can share with you if you would like. It's normal for puppies to lose a little weight the first couple of days but they should gain it back by day 4 or 5 and some never lose weight.
Your puppies should be taken to the vet between days 3-5 for dewclaw removal and tail docking. I'm a little concerned that your vet will not know the proper distance to dock a Yorkie's tail so if you can have someone go with you to the vet for this that knows where it should be done that would be great. If I were closer to you I would offer to go with you but I'm halfway across the country.

Please PM me with any questions, I'd be glad to help
Teresa