Can I pay money for my 14 years old child to take care about 12 old child and claim the payment as child care expenses.

No, you cannot.

.15 The term eligible child care provider refers to an individual or organization providing child care services. Where the child care services are provided by an individual, the individual must be a person other than:

• the father or mother of the eligible child;
• a supporting person of the eligible child;
• a person in respect of whom the taxpayer or a supporting person of the eligible child has deducted a tax credit under section 118 for the year; or
• a person who is under 18 years of age and related to the taxpayer.