Yes - if you and your child (or anyone else you’re applying with) are in different priority groups, you can still apply together.
You’ll just need to apply under the lower priority group.
For example: if you’re in Priority 1 and your child is in Priority 3, you’d both apply in Priority 3.
Important: Applying in a lower priority group will affect your position on the waiting list, so make sure you’re happy with that before submitting a joint application.
If you wish to keep your applications separate in order to remain in different priorities, please apply separately.