No she is totally not!
If you're talking about Jenni Barber the actress, the was 23 in 2006. I'm not sure when her birthday is, so I can't be sure about it, but I think she's 26. I know for (almost) sure she is not yet in her 30s, and that she wasn't born before or during the 70s.
I only know of 'Jenni' Barber. She is an american actress who stars on the children's telivision show The Electric company!
Jenni Honkanen was born in 1980.
Alexis Jenni was born in 1963.
Jenni Screen was born in 1982.
Jenni Murray was born in 1950.
Jenni Muldaur was born in 1965.
Jenni Dant was born in 1982.
Jenni Olson was born in 1962.
Florian Jenni was born in 1980.
Jenni Davies was born in 1980.