As group ad director for NatMags' weddings group, Vernhettes' remit will cover You and Your Wedding, Cosmo Bride and website youandyourwedding. co.uk.
She succeeds Shireen Ridgway, who left the company in August, and will report to Meribeth Parker, the wedding group's publishing director.
Vernhettes joined Conde Nast in August 2005 on a 12-month maternity contract after a five-year stint as ad director of contract publisher Cedar Communications, whose clients include Tesco and camera manufacturer Nikon.
NatMags' two wedding titles have a combined circulation of 108,113.
The publisher recently revamped youandyourwedding.co.uk to include directory searches and more community elements.
At Conde Nast, Camilla Newman has returned from maternity leave to resume her role as ad director on Brides.
Separately, NatMags has announced that its parenting title Prima Baby has signed a two-year deal to co-sponsor the main stage at the Baby Show in London and Birmingham from next year.