Would a trust not have to be created for the child "to hold" the funds from Aunty until the child attains majority ?
If so, the trust would have to be administered by a trustee(s) for the benefit of the beneficiary child.
On the child attaining majority the trustee's obligation would be to deliver up the funds or otherwise account for them to the beneficiary.
I cannot see how the parent could "gift" the funds from such a trust to themselves during the currency of the trust.
Remember that the funds in the trust are the effective property of the child.
For a parent to "gift" the funds to themselves would mean that the funds were destined never to be returned to the child. The concept of a gift is that of something received with permanent entitlement to full ownership. For example, if I buy you a mobile telephone for your birthday it then becomes your permanent property in absolute with no lien on it of any kind.
You cannot gift someone else's property to yourself.
A parent might be a trustee of the trust fund and take effective control of the funds. However, that is nothing like taking ownership to the funds in the guise of a gift and would still require accounting for the funds within the terms of the trust deed !