oh my goodness...this struck a cord with me in regards to my now 14 year old (we both have survived the preteen years I am happy to report)
Nine is a tough age. They are growing in both mind and body
at levels and pace that is a whirlwind to us as parents and also a whirlwind to them as well.
For no apparent reason they are suddenly angry, when before they were happy. It can take the smallest thing to set them off and then just a little effort will bring them back to earth.
When my daughter had/has issues with friends (and there were MANY at that age) we would find a spot to talk about it. ( I also have a 12 year old son who is soon to be 13) Yes, the hormones are running wild around here. Taking the time and having a quiet place to talk really helped us out. It was actually more about her talking and me listening and trying REALLY hard to not try and fix things for her. This is the hard part of parenting. The wanting to fix it and take away the hurt feelings or sadness.
Over the years, this has become a check in process for us both. She tends to get angry quickly but I am more of a slow burn kind of person.
Sometimes I wish I could more like her in that she gets upset, deals with it and moves on easily. Most times I let it simmer until something sets me off and then I deal with it. Basically, I am the 9 year old.
Hang tight, listen to her and when she gets uppity, ask her what the real problem is. Ask her to tell you about what led to the outburst and tell her you will love her regardless, but that you want to help her feel better about what is troubling her. And then shut up and listen.
There will be tangents, there will be crying jags where you cannot understand a word she is saying, there will be moments of apology where she is truly upset that she was mean to you. Reassure her that you love her and will always listen. Tell her that you were once her age and can share your wisdom when she wants to hear it. Most of all, know that the hormone levels are raging around in there and is contributing to what I call the Sybil complex. You just have to stay cool and calm and love her thru it.
As for food on cruises. Wow.... so hard to curtail the impulses of a 9 year old who will be surrounded by pizza, burgers, hot dogs, fries, ice cream etc.
Heck, I am 49 and have been on a "diet" for most of my adult life. When we cruise, I get small amounts of all my favorite foods and eat only that. No second go rounds, and lots of veggies and smart fruit carb choices. Desserts are harder because I really love desserts that I would never make at home or purchase at a restaurant. This is my downfall.
I allow myself one ice cream cone during the day and 1 dessert in the evening at dinner.
It has made me very careful about my choices to know that there will only be ONE dessert. It better be a good one. lol
Perhaps, help her choose grilled chicken over the chicken tenders with some lower calorie dressing as a dip instead of barbecue sauce.
Select a veggie or fruit as a side. Or if she must have the fries, bring a single serving on a smaller plate. And then go with veggies or fruit if she is still hungry.
The family as a whole can make smarter choices without bringing the focus on only HER and what she can eat. Limit the fatty foods for everyone and eat in moderation what you normally would eat at home.
I am sorry this is so long. I absolutely feel for you and I know how hard this is. But keep your patience and stay in love with her even when she acts a bit crazed. You will all be okay if you stay open and talk it out.
Have a sensational cruise.
PS. Don't tell them about it until you were planning to. Threatening to take away what the family needs will only lead to resentment that will add to your DD stress (and yours too)