This ''problems'' only shows that chages has to be made, in one way or another. i'm really sure we will see it in the future, not for Anne (i'm sure she doesn't even care about it), but for William's kids.
Have equality in some things but not in others don't make sense. If Charlotte is upper in the line of succession, is not logical that Louis future children could have higher rank than hers. The logical thing would be: or all are HRH or none.
Or an hypothetical situation: If George would have 4 kids, 3 girls and then a 4th boy. the 1st one would be the princess of Wales by her own rigth, no? the boy a duke. the 2nd, could be the princess royal? even when there is no precedent. and the 3rd girl? just nothing? Again, the logical thing (with a 2020's look) is or dukedoms for all or dukedoms for none.
Or if William is still the King, will the 1st girl get a dukedom when she merries? or will it be given to her husband? Is easy to see acusations of sexism even today...
The problem is that the PL established in 1917 doesn't correspond with the 2013's. In actual times, those changes would be necessary at some point.