Sometimes spouses don't agree on parenting approaches.
Why should it be any different when it comes to your child having an eating disorder? There are multiple reasons why spouses disagree when it comes to your child having an eating problem.
1) Their relationship with your child might be different from yours and they may feel they know less or more than you about what is going on inside her.
2) They may spend less time with your child and have not seen and heard some of things you have.
3) They might be in denial because if their child has anorexia or bulimia they may feel guilt and that it is their fault.
These are difficult emotions to deal with.
4) If there are already issues in your marriage, you and your spouse may have animosity toward one another; to the point where you say black and they say white.
If you see a problem they are going to see it differently because of negative feelings toward you.
5) They might be scared to admit their child is ill because they have to face the possibility that their child could die.
6) They might be afraid to consider an eating disorder because they will feel helpless and not know how to help.
One of the things I would encourage you to do if you and your spouse don't agree; is to step back and objectively consider if any of these issues may be going on in your spouse.
Sometimes we are quick to judge the thoughts or motives of those we love or loved in the past, especially when we believe we know this person well.
The worst thing you can do is judge and accuse your spouse of not loving their child or they would agree and join with you in addressing it.
This will only result in defensiveness and the likelihood that communication between you will be even more difficult.
We all know this of course; but it is one thing to know it and another not to act on emotion when stress levels are high.
None of us are above saying things we now wish we could take back.
This kind of accusing statement is often the last ditch effort to get your spouse to see things your way (whether you are right or not).
It is understandable but it usually backfires.
When you are able to be objective and calm you increase the chance that your spouse will take you seriously.
It also gives them the opportunity to rise above their own feelings like fear, denial and habitual negative emotions about you.
Keep the conversation child centered as much as you can versus spousal relationship centered.
If either of you start veering down the path of old behaviors and past experiences, try to bring the discussion back to your child and your objective concerns about her current struggles.
Stay in the present as much as possible.
It might be helpful to even make an agreement with each other that you will both stay in the present and focused on your child as much as possible.