A recently-published study in the U.S. purports to demonstrate that the children of lesbian mothers are more likely to be on public assistance, more likely to be unemployed, less likely to be employed full-time, more likely to be cohabiting, less likely to be married, more likely to have had an affair, more likely to have had an STI, more likely to have been in therapy recently, more likely to have recently thought about suicide, more likely to have been raped, and more likely to have been molested by an adult.
The only problem?  There is no data to support the conclusions of the study, which was done by a right-wing sociologist who, among other things, defined a queer parent as anyone who had a same sex relationship (of any duration) while a child was growing up.
Fortunately the problems with the study are being widely identified.  See for example this Huffington Post article: http://www.huffingtonpost.com/zinnia-jones/regnerus-same-sex-parents-study_b_1595213.html
Other, credible research finds that the children of a two parent lesbian household are as well-adjusted on  all indicators of psychological health; and actually are more open-minded and tolerant that children raised in two parent heterosexual household.