Not necessarily - I can and do switch my pronunciation of (for example) cook or book in the same conversation. Broad Lancashire one moment, and talking 'dead proper like' the next. I don't do it deliberately.

Agreed, it is quite common for people to have a mixture of accents. I respect her for speaking naturally and not thinking she has to speak with a London accent to satisfy some Southern critics. Good to hear someone talking properly as she does most of the time, just work on pronouncing words like vote correctly as well.