Some buns can simply be more vocal than others.
If a normally silent bun begins to squeak they may be in pain or scared and if Fluffy is normally silent I would be concerned about her squeaking.
Some rabbits are very scared about being picked up so think how you pick Fluffy up. Could anything you do be causing her possible pain or fear you had not thought about? Some of my buns have hated being picked up over a height and have coped better if I have got down to their level and been firmly holding them before I stood back up.
Scruffing is something most rabbits dislike but sadly most folk are told this is how to pick up a rabbit.:roll: It may be easier for us but I doubt its easier on the bun.
Pumpkin prefers to be spoken to and stroked before I slid my hand under his chest and my other hand under his bum to lift him up.
Teasel prefers a two arm scoop so all her feet are craddled upon my forearms.
Doodee will rip the flesh off your arm if you try and pick her up so I use what *vic* on here refers to as her patent bunny elevator method [rabbit carrier].
My noisy rabbits make a range of squeaks [feed me NOW/ pet me I am gorgeous] honks [where is the food, what is that, where are you] grunts [I am disgusted with you/ I do not like THAT rabbit] and soft tooth grinds [ you hit the spot now keep rubbing it].
If however they make a high pitched squeak I check if they are hurt or hurting.
Get to know what is normal for Fluffy so you can spot if low pitch squeaks get higher if for Fluffy this is how you 'talk' to people.