Confused about FVRCP for kitten

I have received some confusing information from the shelter and our vet regarding how many shots my little one needs:

Lulu came to the shelter at approximately 5 weeks old as a stray and was given the FVRCP shot. When I adopted her at approximately 11-12 weeks I took her to our vet where she received a booster. We were told to make another appointment for the 3rd round in about 4 weeks ( later today).

The lady at the shelter said that the vet would tell us that kittens need 3 rounds, but that 2 are really enough and that's what they do at the shelter.

I read in one of the threads here that the last shot needs to be given after 16 weeks, so I was leaning towards keeping the appointment. However, I just looked at the paperwork from the last visit and it states:
"reminder: VX: FVRCP BOOSTER - 1 year"

What does this mean, that Lulu needs a booster in a year (then why the appointment for today?), when she is one year old? Was the lady at the shelter correct?

If you give your kitties this vaccine, i believe it is suggested to have around 6 weeks and again at 1 year of age or one year after their last dose.

As I understand it, the number of shots given doesn't matter so much as the timing of those shots. For the best immunity, the last shot in the kitten series (whether you do 2 or 3) should be given after 16 weeks of age. And then a booster a year later. Vets give names to their services to put it on the bill, so probably "FVCRP BOOSTER - 1 year" is the name programmed into their computer.