milk and bread are not a good choice. Dogs often do not digest milk well. If you must use a grain, I suggest sticky rice. A chicken leg is good if raw, never cooked bones. An egg is good. It might be better to find a good quality kibble.
You don't want her to have accidental puppies, so spaying is highly recommended. And getting another puppy right now will triple your work. You need to spend quality time with each pup separately and time with them together. If you don't they will loose interest in you and bond with each other. That will make training them so much harder.
Hold off on the second pup until this gal is at least three and is healthy and trained well.