Tenants request for reason

Possession - Section 8 and Section 21

I issued a Section 21 last night to a tenant and she accepted it without the abuse and resistance I was expecting. She has since emailed asking for me to put, in writing, my reasons for issuing it. These include:- late payment of rent, boyfriend kicking the door down, quoting regularly to me that smoke alarms and carbon monoxide detectors need to be fitted, she wants to be reimbursed for the cost of having the carpet cleaned, she wants to see the electrical installation certificate, she will not be staying long term I am rude to her etc etc…… Do I actually need to give her a reason if she is not bright enough to see for herself? I wonder if she wants this information for HB but can't see that it would help her cause if I gave honest reasons!