Do you think it will remain behind Aquaman next weekend (1/11-1/13). I see it could be close which could make it a mute point. I don't see any newcomers challenging them for #1. If Aquaman drops similar to Wonderwoman the next two weekends, it would be looking at a 4th weekend of around 21 million. If Mary drops similar to Greatest showman the next two weekends, it would have a 4th weekend of around 22 million. I think both will drop a little harder, but do think it could get interesting. Greatest showman lost 400 theaters from weekend 2 to 4, Wonderwoman lost 200 theaters. not sure what Aquaman and Wonderwoman will project to, but neither has a big challenger that will steal a lot from them, next weekend having more new releases than this weekend.You're right about it being to early for proper tracking. Late December releases are often the bane of box office statistics! You never know for sure how they shake out until a month later. This coming weekend and next week should be a better indicator of MPRs long term performance.
Sing is going to be hard record to break, but it is doable with the right combination of events. There is a lack of competition for either MPR or Aquaman for a nice long while; they are both likely to still drop in the rankings but stay more stable. If she breaks more on the The Greatest Showman (also never hit #1) side with low consistent drops, Disney might be more inclined to push for a rally around awards time to extend it's range of good legs. I still only rank it beating out Sing for that spot at 10-15%, provided MPR goes the most predictable drop %; could be a lot higher if the loss week-to-week stays really low.
Too Early To Track Tracking for Mary: after 15 days = 119 million (84th now among those never #1, made almost 1 million more than Sing did on day 15, but still 71 million behind where Sing was on day 15)