I was wondering if a lesbian couple can have a baby with both their DNA? I heard about it that had something to do with bone marrow and the couple can have a baby with both their dna

Nope.

Haploidization?

http://ask.metafilter.com/63323/How-do-two-women-have-a-child
Too many "May" and "coulds" nothing definite, from an article written in 2007 referencing one from 2002.
Also not enough gametes.


The use of this technology has a high risk of creating damaged people and therefore I don't think it should be allowed to go aheadhttp://news.bbc.co.uk/1/hi/sci/tech/1769356.stm

Not at this time, any research is experimental at best and years away from any practical use.