New figures reveal that 105 children in the region have sought help after being sexually abused by a female in the past year.
The statistics, released today by the NSPCC, also show that counsellors at ChildLine's Yorkshire and North East base spoke to 594 children in the area about sexual abuse.
In total, ChildLine volunteers counselled 12,268 children nationwide who cla
imed to be the victims of sexual abuse.
Although figures show that the majority of calls were in relation to abuse by a male, the findings show that more children are reporting assaults from a woman, usually their mother.
A total of 2,142 young people across the UK told ChildLine they had been sexually abused by a female.
Of those callers counselled, 1,311 told ChildLine they had been abused by their mother.
The overall proportion of children calling ChildLine about a female offender has risen from 11 per cent of sex abuse calls in 2004-2005 to 17 per cent in 2008-2009.
One 14-year-old boy told a counsellor: "When mum drinks too much she comes into my room, undresses me and makes me have sex with her."
Lee Mitchell, assistant director for ChildLine Yorkshire and North East, said: "Most sex abuse calls to ChildLine come from girls saying they were assaulted by a male. Large numbers of children, however, say they were sexually abused by a female.
"Many people find it unimaginable that any woman – let alone a mother – can sexually assault a child, but that is a dangerous assumption to hold. It is so important therefore, that we remain vigilant and act on any concern, irrespective of gender.
"Sexually abused children are often driven to despair because they don't know who to tell. Even when they summon the courage to speak, they are scared no one will believe them.
"We have to listen to these children, take their concerns seriously and give them the protection and support they need."
He added: "In the last 10 years, ChildLine counsellors have helped more than 100,000 sexually abused children. Sexual abuse is still one of the main reasons children contact us. For many, it is the first time they have told anyone about their ordeal.
Young people can contact ChildLine on 0800 11 11 or through website www.childline.org.uk
