The Old Cotswold Legbar is a Hybird made with Cream Legbars cross with other chicken breeds. If you have a cotswold, then I don't know that you will be able to determine the gender untill the combs grow out which could be 4-5 weeks of age.
If these are pure Cream Legbars, then the chipmonk stripped chicks are females, and the ligher color chicks with the large white spot on their heads are males.