Depending on how close you and the newly sober friend is, and how much respect you have for him/her, I’d say yes, it may be disrespectful. Remeber, this person is still an alcoholic, and battling it every minute of the day.
Additionally, I’m personally opposed to getting drunk in front of children, so I’d say it’s a bad idea in that regard as well.
Those two statements are making a couple of assumptions, I admit:
That the sober friend isn’t okay with alcohol being around…if he/she is, then that’s another story, and
That the kids are fairly young and the parents aren’t okay with alcohol being around. Again, if they are, 'nother story.
Bottom line is, check with the people going on the trip. If they object, don’t bring alcohol, out of respect for their wishes/beliefs.