Marriage Visa

I am a British citizen. My fiance is an Indian national came to the UK to get married. Now we are married but going back to India means she wont come back to UK as India is in Red List. We dont know how long India will be in Red List. She had two vaccine doses in the UK, therefore she had a Covid passport.

Regularising her visa is being considered but her visa expires on 3rd August 2021.
Is there a way out to get her an extension for 2-3 months (she already got extension from 30 June till 3rd August due to Covid).

Please advise.

If she is on a fiance visa, your spouse can now apply directly for a spousal visa from within the UK.

Or did she arrive here on a Marriage Visit visa? If yes, why was that visa chosen, as that requires her to leave the UK after the marriage?

She came on marriage visa.
She got extensions till now due to Covid & cancellation of flights.
Yes, she can aply for spouse visa as well but switching takes time and her visa may expire before that.