"We have a sensitive, high needs child and he often says how he wishes that she didn’t exist, wasn’t around etc etc" <<< Huge Red Flag here!!!
Please consider reading the following:
What Happened To You? (I highly recommend starting here with the audiobook for excellent conversational immersion experience)
and finally, The Body Keeps the Score
I think you will find these enlightening in many ways. So much love & light to you and your babies.
To the book?
If you'd like to check it out from a library: https://www.worldcat.org/title/deepest-well-healing-the-long-term-effects-of-childhood-adversity/oclc/967029136 (The one I read was an eBook edition checked out from my local library.)
If you want to buy it, then Barnes and Noble has paperback, eBook, and unabridged audiobook versions (link is to author as I couldn't link all versions at once), Amazon has those and hardback, and you could probably find them at (or shippable to) your local bookstore(s), too--my local independent one can get paperback, hardback, or CD audiobooks of it shipped to them for pickup.