How does it make a difference whether she talks in Hindi or English...a person should talk in a language in which he/she feels comfortable and can easily express.
And who told you that Hindi is the only Indian language we have? English is also widely used in many parts of India such as Goa, North East, Kolkata.
Doing a movie in Hindi does not make it compulsory for her to speak in Hindi...it's good she is speaking in the language that she is comfortable in and the one that suits the channel/media (rediff.com) and the occasion.
Also, she is just not speaking for the Hindi audience. She should speak in English because most of the people who use the Web understand English, but not everybody understands Hindi.
One thing is for sure, she knows both the languages very well, which is very good.