"
Local Portuguese Woman [with excavation site as backdrop] -
That has no logic. What thief breaks into a house, takes the child away, murders her, carries the child on his arms in everyone's sight on the street and then comes here to bury her in an place that is only ground rock? Only a fool would do that! That's all I have to say about that. [laughs at the idea]"
http://joana-morais.blogspot.com/2014/06/goncalo-amaral-there-was-no-breaking-in.htmlThis lady in the street is talking common-sense, however note that
Part 1 of SY theory ("thief breaks into a house") which if a window is unlocked does not require force, is good.
Excellent theory so far, because that is exactly what burglars do, and it's confirmed by the open shutter and window.
Part 2 of SY theory ("takes the child away") is rubbish.
No burglar would do that, as that lady on the street can easily tell SY.
The answer is to retain part 1, but replace part 2, with the SIO actually imagining they are a burglar, they think everyone is out, open a shutter and window, but then inside they see children.
The obvious result will be that the SIO turned burglar will immediately flee empty-handed (confirmed by the fact that no material items were stolen), and any awakened mobile child will simultaneously flee in the opposite direction, out of that room into another room (confirmed by the fact the child is missing from the first room).
That doesn't completely solve the disappearance, but it is the first step IMO.