This was the first video I've taken the time to watch because the baby she's feeding is only four days old and very, very tiny. This chick was rejected by the parent, hence the hand feeding. As you watch you will see how tricky it is to feed a tiny wiggly chick. I do see the crop has formula in it, she has to feed every 2-3 hours around the clock at this age. Doubtful this little one could go between 12:00 pm -5 or 6 am since he's not growing well according to the breeder. I haven't gone to her videos to see if this little one has any updated videos of progress yet. I don't see her changing the formula in the spoon for a warmer formula from a bowl which could be very problematic for a chick... formula too cool ( less than 105-107 F) could chill the chick and slow the crop down in digestion... then you've got more problems. I also think with this tiny chick she could have used a heating pad covered by a towel on her table to keep the chick warm during feeding. I'm not sure if the feeding response could have been better if formula was kept warm including a warm surface to sit on during feeding. I'm sharing this video so you can see how difficult it is to hand rear when they are this little and prepare you for what could happen. If you don't have a brooder ( a separate container) ready to place chicks in complete with heating, bedding, thermometer ( digital that includes temperature and humidity), a special feeding spoon ( if you choose this), several containers to mix formula in .. including a separate digital thermometer for measuring the temperature of the formula, now is the time to have all the supplies you'll need if you end up having to take care of any little ones. Be prepared to mix formula and keep it heated while you are feeding ( formula tends to thicken after you've mixed it so you'll also need a separate small bowl of extra warm water to thin the formula if need be. Don't feed unless the temperature is correct! Consistency of formula is very important for each stage of growth so you'll need to learn about that too.
There are a lot of good links for you to read in the thread titled Baby GCC's Zara included as a link just above my first post in your thread. I will also look for more helpful videos and budgie related articles.
I went back to the commentary on this video.... this chick did not survive.