Buy-to-let house selling advice...capital gains, allowable deductions etc.

Description of support work: Hi

My landlady that I live with is selling a buy-to-let house and has had a lot of problems with her tenant. She has an eviction notice going through as she has sold the house but it has been a stressful time for her with unpaid rent etc and she can't wait to get the house sold and debts the tenant has caused sorted. She's now trying to get her head around the sale of the house, whilst being very stressed, so I thought I'd get her some advice so she can take some of the pressure off and understand the next stage in the process better.

A little bit of info:
She has 3 houses on a buy-to-let mortages, the one we live in at the moment, the one she is selling and another one.
She lived in the one she is selling for 5 provable months (Nov 12-Feb 13) with council tax bills, utility bills, electoral role, but then relet it.
The house has been improved over time from her pocket (new bathroom etc), she started the mortgage with her partner and then changed mortgage company and put it in her name.

She has no idea about capital gains tax (how much she will need to pay, what amount she pays tax on, what happens with her deposit etc) and the best way to approach it all, if there are any allowable deductions or ways around it etc.

I've put £70 but I had no idea really. Hopefully this is detailed enough for you to see how much advice would be needed so feel free to chip in with any other ideas or offers.
Talking by phone would be best, but email would also be ok.
Proof of credentials a must of course :)

Many thanks
Jo