Well, if any abductor(s) was/were was in mid operation with a plan to steal every child wouldnt matter if it were 10 paces! Oh, so bothering Jane or a neighbour deemed tooold (never mind other neighbours around) was considerate? Are you kidding me? Absolutely preposterous! I do not believe for a nanosecond you would do the same, neighbours or police are always first port of call, but of course, if you say so.....
She got immediate reaction and immediate unquestioned help from the people sitting at the table. All young. All fit and athletic. All capable of covering the ground quickly, the women - with the exception of Jane Tanner - to help Kate and to check on their own children who were also alone.
In my opinion had she remained on the balcony screaming her head off that too would have been subject to criticism.
I don't know how I would have behaved in the same situation, but with the benefit of hindsight I consider her behaviour was entirely appropriate.
She had discovered that Madeleine was missing.
She immediately searched the apartment. Madeleine wasn't there ~ neither was there evidence of a threatening adult in the vicinity.
She immediately raised the alarm and got the search for her daughter started in the shortest possible time.