Not sure whether the below clauses can help you in clarifying:
Please be reminded of the following procedures on UM handling on Singapore Airlines’ flights:
1. A child under the age of 5 years cannot travel unescorted for safety reasons.
2. An unaccompanied child aged between 5 and under 17 years must be accorded UM handling as long as they are not accompanied by an adult passenger 18 years old and above on the same flight and class. Between 5 and under 17 years old: UM form must be submitted if they are travelling alone. Between 12 and under 17 years old: UM handling can be declined if the parent/guardian signs a ‘UM Assistance & Handling Waiver’ Form STRA 1161. This form is available at check-in.
3. UM handling must be accorded even for cases where parents/guardians and child are travelling on the same flights but in different cabin class.
4. Travel agents will be required to verify the parents/guardians booking with Singapore Airlines’ AROs in cases where the parents/guardians are travelling on the same flights but in different class.
It is mandatory to indicate the parents/guardian PNR as TCP in the children’s PNR. If there is any booking made for passengers aged 5 years and 17 years without accompanied adult passengers, please ensure that you comply with the above procedures. Otherwise boarding will be denied for non-compliance.
You should be able to get UM handling waiver as per paragraph #2 above, as long as you are between 12 and 17 years old, and meet the requisite conditions.