Monitoring is an important phase of recuperation. The hard part is to monitor without becoming paranoid (like I tend to do).
I am guessing that what the vet means by checking her limbs and shell is to look for signs of an illness that hit her blood (sepsis).
Now don't get scared, it is just something to check to make sure she is fully recuperated (RES can hide illness quite well).
Just take her out each day and look for pinkness on her plastron, the seams of her plastron, and her upper limbs. Trust me; if it's there you WILL notice it right away.
No vet is perfect, but from the sound of it yours seems to know what he/she is doing when it comes to RES, so keep following his/her advice.
As for an RI returning - Yes, just like a cold a RES can get an RI more than once.
Just keep the symptoms in the back of your mind (the nose bubbles, swimming with a tilt, lethargic, loss of appetite, etc.), again, don't obsess over every move (like I did)
Little bubbles once or twice are not a reason to run to the vet; it's
frequency over a
short period of time.
For example, if I cough once or twice and have no other issue, it's no big deal.
If it progresses to coughing more often, feeling tired all the time, and not really wanting to eat, then it's time to wonder.
If I cough all the time, sleep all day, have no interest in food, and have a fever it's probably time for me to see the doctor.
The same applies to RES. Just replace the symptoms in my example with: Bubbles from the nose, lethargy, loss of appetite, puffy eyes, etc.
I think you get the idea.
If anyone spends time with their RES daily, even if making a mental note as walking by, they will quickly see signs of a potential illness and that is the time to raise the radar and put the little one on "illness watch"
I think you will do just fine

PS - support is what we are all here for - whether it be looking for it, or giving it!
Can't wait until next week to hear Dumbork is doing great!