My question involves a child custody case from the State of: FL

-Child lived with both parents for approx. 20 mos.
-Father on birth certificate, no paternity test.
-Mother is disabled but has had sole physical custody of child for 5 years. Child is 5 now.
-No parenting plan was established when child support was ordered and enforced by court. Unsure why this did not happen.
-Mother has refused to sign plan brought by Father repeatedly, but, has excellent relationship with father and allows him to see child whenever he wants,
overnights, alternating holidays etc etc. Dad's visitation is extremely liberal.
-Mother wants to relocate to a Northern state as about to get married to long term partner in professional field.
-Child will be able to attend better schools, etc etc.
-Father does not want this although Mother has no issues with allowing ample visitations, absorbing travel costs etc.
-Neither Mother nor Father are in anyway unfit (although Mother is disabled)
-Father consistently pays child support as it is drafted out immediately.

Can Mother leave the state permanently without Father's express permission? How should Mother approach this? Father refuses to discuss this reasonably and stonewalls at every turn.

Thanks much, sorry for bizarre wording. Trying to stick to the facts.