Having a lot of experience in this area...
One should Not introduce anyone new for at least 2-3 years, after a divorce or separation....if there are children involved
The shear shock of what has already happened....and now a new person is on the seen, is too much! for children.
You can have someone for you, but that has to be kept from your children, until a good portion of time has passed.
It is harder for children, they have lost a parent out of the family home....they may have even had to leave the family home...new school, friends.
Plus they have to have visits now with the other parent!
No one should then subject the children to a complete stranger, just because it makes you happy.
It is always the children who come off worse in this.
The kids need you....and nothing else to complicate their very fragile world right now.