It depends on what you mean about "what can be done." The survivors can mourn, the deceased can be buried, and the estate can be handled in accordance with applicable law.
What are you trying to learn?
No that person is an adult and child support stops at 18.
Essentially, yes, the estate has to settle all debts. That includes the sale of assets.
The opposite would be an adult or grown person.
providing a home for the childhaving contact with and living with the childprotecting and maintaining the childdisciplining the childchoosing and providing for the child's educationdetermining the religion of the childagreeing to the child's medical treatmentnaming the child and agreeing to any change of the child's nameaccompanying the child outside the UK and agreeing to the child's emigration, should the issue arisebeing responsible for the child's propertyappointing a guardian for the child, if necessaryallowing confidential information about the child to be disclosed
There is not a way to adopt a person at the age of 20. After the age of 18 they are considered an adult.
How old is this person? Child or adult? 18 year old that still acts like a child? I do believe 18 is the age for most states to consider it legal for them to enter into contracts. Unless you co-sign with the person you are not legally obligated for their finances. Under 18 tho, you are responsible for any damages or financial crap they get into .
Mature
If you live in the US....no. Having a child does not emancipate a minor.
At 18, the person is no longer a child. He/she is now an adult not a child. No custody order can be enforced on an adult.
A power of attorney is only used to represent a living person. After death, they would apply to the court to be appointed executor of the estate.
No. Being pregnant/having a child does not emancipate a minor.
There is no need for "legal process" unless the person being asked to leave has a lease or is a part owner of the property. If the issue is parents wanting an adult child to leave their home, all that is needed is for the adult child to be told to do so. The adult child has the right to take all personal belongings and those items that they purchased or gifted. If an adult child refuses to leave voluntarily the parents may enlist the assistance of the local authorities (hopefully that would not be necessary).