Hello Natalie,
That is very cut throat. To put a baby bird on such a tight schedule really does lack the love and care that a mother bird would give them during the weaning process.
While your vet recommends no seed and only pellets, that is not ideal. Cockatiels do have a small amount of pellets in their diet. Yes getting them to eat pellets is great, but forcing it upon them is a bad move.
I have weaned all of my babies using millet. Yes it's parrot junk food, but they can learn to hull seeds with a food they enjoy, and are happy during the weaning process. Food is food at the end of the day, and it is important that they are eating something (anyhting!) during the weaning process or they will lose weight and become at risk for malnutrition and starvation.
I had a similar conversation with my vet about one of my baby birds one time, I had gone in for her foot issues but when the vet saw she hadn't weaned yet, he tried to put me on a tight schedule with her. I changed vet after that.
Forget the numbers, forget the "schedule".
When you wake up in the morning, weigh your bird. If she is still 73g (with her crop empty), then you feed her 7.3CC (it doesn't have to be perfect to the tenth decimal). If she pulls back a first time, wait a minute, then offer more. When she pulls back the second time, feeding is over. When she's done, offer her some adult foods. Some steamed veggies mashed (serve warm for youngsters), or some soaked pellets, or a little millet. You can feed it from your hands, or a spoon, or a small plate or food bowl. Don't force her to eat anything, just leave her to explore.
Monitor her. When the crop is almost empty, feed her again the same amount. Again, after food, offer the adult foods.
Between feeds, offer her adult foods throughout the day.
Keep going until night time. It could be 3 or 4 feeds per day but doing it this way, you will know what her body is asking for. Not all birds are the same. Environmental factors can alter speed of digestion for eg, having 5% less humidity.
Overnight, allow her crop to empty completely. When it is the morning, her crop should be empty. Now you weigh her again, today she should weigh more than yesterday. So now use the new weight to determine how much food to feed per feeding.
As she weans, she will take less per feeding. When you see she is constantly eating less than the feed dose for each feed for a couple of days, reduce one feed per day, and spread the feedings out evenly. So if you are doing three feeds, they should be morning, noon/afternoon, and night. When it's two feeds, they should be late morning, and night. And when down to the last feed, it should always be nighttime feed. This ensures our little ones always sleep with a full crop to get them through the night.
During the weaning fledgling period, she may lose weight, ready to take flight, but she should still be eating (it will be more adult food and less formula).
A cockatiel weans at about 10-12 weeks old, so you still have a way to go
I could talk and talk about this for a long time as raising chicks is more than a short reply, but hopefully I got all of the important stuff in my post!
Please do post any questions you have
edit; might help to write all the feed times and weights down, keep a journal of sorts to help guide you
