I would not go on runny poops alone!!!
Anyone, milk-intolerant or not, who has no dairy in their system, develops a temporary lactose intolerance of sorts. If you were to get ill and not eat any dairy for ten days, and then go and introduce dairy back in to your body, you would have runny poops and tummy cramps, too!! So it is not really enough to know. And, to boot, even kids who are not milk allergic and are on formula often have a difficult few days of transition when taking to cow's milk as a drink, and can have very runny poops when switching to cows mil. Our GI-paed told me that if poop was the ONLY problem and it was a bit of diarrhea, to ignore it and persist! Watch for more severe symptoms like mucousy poop, blood in stools, skin changes, behaviour changes, complaints, and so on.
I would say that if she has no mucous and only runny poops, give her a bowl of weetabix and milk and see if she gets any full-blown symptoms, and ignore the runny poops for about 7-10 days. If they persist longer than that, then you can look at them as a symptom, but on their own without any mucous or blood I would not assume she has not outgrown it.