Lieserl Einstein was born in January 1902. The general theory is that she was given up for adoption shortly after her birth, probably because of the damage that having had an illegitimate child could have done to both Mileva and Albert's burgeoning careers. Almost nothing is known about Lieserl's life. Some think she might have been born with Down syndrome. Some think that, based on letters from Einstein to his wife, the baby died as a young child from scarlet fever. Others think that, unable to put her up for adoption, Mileva left her with relatives in Serbia. Not that a lack of information is cause for a lack of speculation! Authors have written fictional novels involving Lieserl, wondering about what her life might have been.
By Shana Priwer & Cynthia Phillips, Ph.D.http://www.netplaces.com/einstein/later-years-family-and-humanitarianism/einsteins-children.htm