VISA EXTENSION

[MarthaLucia]

HI, I wonder if someone could guide me please about an application form. I have read all the options to apply for my mum’s visa but I can’t find what kind of visa she can apply now.

My mum is 76 years old and her VISA SETTLEMENT TO JOIN/ACC CHILD expire in few months.

She was here in UK
• TOURIST VISA VISIT 6 MONTHS (visit for 3 months in 2009)
• TOURIST VISA VISIT 6 MONTHS (visit for 5 months in 2010)
• VISA SETTLEMENT TO JOIN/ACC CHILD 6 YEAR VISA (visit for 4.5 years) and now she is back in the UK but this visa expires soon.

I am BRITHISH CITIZEN and we can provide evidence that we can support her financially as dependant.
I will love to apply for SETTLEMENT but I am not sure because she was here 4 and half years.
At the moment she is in the UK.
What kind of visa should I apply?
Many thanks.
Martha Lucia.