The married mum-of-two has always lived in the Bradford West area and has previously been a candidate and member of the Green Party.
Sonja has a solid track record in community involvement.
She is chairperson of community group Upper Heaton Working Together and is membership secretary of the Heaton Township Association.
The UKIP candidate was also a volunteer with Bradford Nightstop - an organisation that provides assistance and accommodation for 16 to 25 year olds who find themselves homeless.
Sonja has also been a Bradford Street Angel which saw her walking the streets of the city on a Friday and Saturday night providing assistance where needed.
She is a governor of Frizinghall Primary School and also of Feversham College - a voluntary aided specialist science school for Muslim girls aged 11 to 18 years.
Sonja is also on a Hate Panel - an initiative that sees local residents meeting up regularly to discuss how police deal with reported cases of a hate crime
Politically, Sonja was a member of the Green Party and stood as a candidate for the Toller Ward (Bradford West area) in 2009.
In 2010 and 2011 she stood as a Green candidate in Heaton Ward.
Sonja joined UKIP at the beginning of this year and said: "I am proud to be the UKIP candidate for this forthcoming by-election and represent a party that is offering a fresh choice in British politics.
"My track record in volunteering and community work means I know what matters to local people.
"Bradford West deserves a MP that cares about the area - not a career politician only selected by a party to increase their numbers.
"In the case of George Galloway, he is little more than a political opportunist desperate to remain in the limelight to keep his Z-list celebrity credentials intact."
UKIP Leader Nigel Farage said: "Sonja is a first class candidate who knows that patch like the back of her hand.
"Voters have become fed up with the empty promises of the so-called big three parties and are increasingly looking elsewhere.
"UKIP is slowly and surely building up a credible reputation in local politics and giving the others a run for their money.
"Remember it was only last year that we came second in the Barnsley by-election to Labour, polling more votes that the Conservatives and Liberal Democrats combined."