Urgent! Visitor visa extension: is it recommended?

[subah]

My mom has a 1-yr multiple entry and it's going to expire in 1 month. I would like to apply to extend her visitor visa for 2-3 months.
However I am wondering if it is recommended.
I am concerned that when we apply for her visitor visa again; would the extension result in a visa rejection?

Also when is it a good time to apply for another visa for her. And how to increase our chances of getting a 10-yr visa.

[aditya_1981k]

I guess Visa Extension can be done only if the reason is urgent or genuine or very serious

It " MAY" effect while applying for 10 years visa