However, the one restriction to take note is that when using the CDA to pay for another child, only children below the age of 6 may use their siblings CDA for their educational needs. Children above 6 can use another childâs CDA for their medical expenses only.enefits of CDA. The savings in the CDA may be used to pay fees for all your children who are attending Approved Institutions registered with MCYS under the Baby Bonus Scheme. These include child care centres, kindergartens & special education schools registered with the Ministry of Education.