We just flew with Jet2 to Faro and used their assisted travel option and we were so happy I wanted to pop some points down as I found quite a few threads asking but not alot of answers:
You have to call to book it, but the operator was lovely. They will ask if you have any mobility requirements as well.
When we checked in at Stansted they directed us to the special assistance desk who made sure we had a sunflower lanyward and directed us to the disabled access security gate (so no need to book fast track). You are spotted by staff and they will direct you straight to the security desk by opening barriers for you.
We were able to leave our pram at the last minute at the aircraft - FYI they didnt weigh it!
At Faro we didnt have any assistance booked but were quickly ushered into a family area where there was no queue for immigration.
On the way back, they made sure someone collected us after check in and took us through a back corridor of the airport into a special security check - the room was quiet and the staff were brilliant, bringing over DDs ear defenders and teddy as soon as we had passed through the security screen. They then escorted us to teh disability chairs and told us the gate in advance of it being on the screen so we had plenty of time to get there ahead of the crowds.
The air stewards were brilliant - DD got upset as we got on the plane and they came over, knew her name, gave her some stickers and high fives and told us to wait on the plane when we landed and they would make sure our assistance was there.
We didnt have to climb down the stairs of the plane, they had a special lift they used. We then were put in our own minivan and driven across the airport and once again taken a back way in, a 30 second walk to the immigration desk. Again, you do NOT need fast track passes which I had brought for immigration (the regular queue was massive) as we were able to access the disability line.
It made travelling for DD so much easier, so much quieter, hardly any crowds. I could not fault them, all of the staff were so accommodating.