My ex and I are finalizing our divorce. We are signing as co-petitioners. I feel that for the most part everything is fair (time with son, child support, splitting of assets.) However on the parenting plan there is a section for Alternative Care. One part of that section is "The following people can not provide alternative care" ... listed there is the name of my girlfriend.

It bothers me to sign the paper because her name is on there out of spite and resentment and not for the welfare of our child. At least in my opinion. I assume she looks at it differently

If I sign it, I am concerned that it will be an issue down the road and I don't want her holding this over my head. However if I fight it now it would obviously delay the divorce and potentially (most likely) lead to my ex making things more difficult. She has repeatedly told me that this is non-negotiable. I am not sure if she would stick to her guns if there was a threat of delaying the divorce.

Facts

1. I left my wife for this girl so rightfully she is very upset at me and the girlfriend
2. I have been with my girlfriend for about 7 months (with the exception of a month break we took).
3. My son did meet the girlfriend (which my ex knows). The encounter was at a indoor playground. She was introduced as a friend. She was babysitting other kids that were there as well. It was basically a playdate.
4. My girlfriend is a social work grad student and heavily involved with child care and development. So there is no danger concern.

How difficult would it be to change the parenting plan to have her name removed down the road?
How would I be able to prove that having her name removed is in the best interest of the child?

The parenting plan just has my girlfriends name on it. there is no social security number or anything like that