Hello and thank you for allowing me to assist you.
Because the Junior ISA is a tax free account there are specific rules about when it can be opened but also when it can be closed.
Money in a Junior ISA belongs to your child and can’t be taken out until they’re 18, though there are exceptions to this.
The registered contact (the child’s Junior ISA will be in their name, but the parent who opens it is responsible for managing the account and is known as the ‘registered contact’) can take money out of a Junior ISA early if a child’s terminally ill.
This money cannot be taken out for the parent's needs unfortunately. The child can take it out when they turn 18 or it can become an Adult ISA.
I know you wanted to know some work around to the law but that is not allowed.