I too am from the UK.
Fleas in kittens are quite normal but they do need to be eradicated.
My advice would be to consult either a vet or the Cats Protection League for advice.
You can by over the counter flea treatments from a pet shop but they are often not effective enough and sometimes can cause other problems.
A vet will not only be able to supply you with a good flea treatment, if you take your Queen and the kittens with you he/she will also be able to advise you about their health, neutering and vaccinations required.
The link to the Cats Protection League is:
Cats Protection
Good luck and I hope your Queen and the kittens have a long and happy life.
Poseidon