Overcrowding due to Room Standards help!

Hi, I bought my first BTL last August, 3 bedrooms, 1 livingroom and rented it out to a family of 5.
The couple have 3 kids who at the time were 9 and 14 y/o twins.
My problem is the youngest is now 10 and her bedroom is only 4.6m²
I am worried about the fines as technically the house is overcrowded due to the room standards.
The twins are also sharing the middle room which is under 6m² so this is technically too small for them also.
What would you do?
Please help

I could be wrong but thought these minimum room sizes apply to HMO’s for the purposes of weeding out bad landlords who are overcrowding their properties.

There was also some ruling a few years ago which said these room measurements was for guidance only. I don’t know if that has changed.

The minimum room sizes can be enforced with family lets under HHSRS, however, there is usually some mitigation if the property has other rooms such as lounges, (see Part X Housing Act 1985). This does sound like it might be overcrowded though. You may need to gently move them on.