and if the question comes to get acceptance by marrying royal blood then that doesn't mean that royal blood should come from nanda's family only..and in facebook girishji gave some logic about durdhara not being dhana's daughter...
if we follow dates then we can find in 320 b.c cgm defeated nanda and became king..the stories which referred about dhana's daughter married cgm they said that marriage happened after cgm defeated nanda...but if we follow date then we can find bindusara was born on 320 b.c..only few months later...so isn't it strange..if dhana's daughter was durdhara???
but still i can give benefit of doubt to dhana is dhara's father theory...due to lack of historical evidence...but you people also have to give benifit of doubt to those theories where its said that durdhara was north-western india's princess...or diodora-a macidonian girl...and i found a book of mr.ayar who told durdhara is daughter of koshala king and was married to cgm few months before cgm defeated nanda