Discretionary Trust question

Miger1

Hi. I have some questions about Discretionary Trusts and I appreciate any info and help regarding setting one up etc.
The history is that my father in law passed away some time ago and left his half share of the family home into a trust for his 3 adult children.
My mother in law is still alive, living in the property and has a life interest in the property.
I was executor for my father in laws will.
My mother in law is in quite bad health now and my wife ( as one of the children) has power of attorney over her affairs. We are looking at getting things in order before the inevitable happens unfortunately.
The problem is that one of their grown up children has long term mental health issues,but is now thankfully coming back from a bad place. We don’t think having a large amount of money at once will help their situation at all and I’m looking at options to help perhaps drip feed them funds or similar?
I’ve discussed this with the person,they trust me and would be happy for me to administer a trust and manage funds for them.
I’ve heard about Discretionary Trusts and I have some questions about these if anyone can help please:
Are they difficult /expensive to set up?
Given that the property is in a trust already, will this be an issue?
Is this something I need to set up quite quickly now?
Are there any other issues/ complications I need to consider?
Thank you so much for all guidance or suggestions 

getmore4less

Vulnerable persons trust may be more appropriate and possible.
That 1/2 the house probably sits in a IPDI trust .

Worth getting some proper legal advice on the options.

How likely is it the person might demand the money?
If very low just managing the money as a bare trust may work.

HMRC has a decent overview on trusts.
https://www.gov.uk/trusts-taxes
https://www.gov.uk/trusts-taxes/trusts-for-vulnerable-people

Miger1

I’ll go to see a solicitor and take a copy of the current will with it’s trust details.