When I went out yesterday to purchase some fruits for the Christmas gathering today, Angela told me something that happened while I was out. Apparently, Esther had 'climbed' out of the walker on her own.
Since Angela was in the kitchen getting something, Esther was roaming around the house in her walker. Just as Angela came out of the kitchen, she saw Esther on the floor with her butt up and her head was on a poster that had fallen off one of the chairs. Surprisingly, Esther did not cry in pain or anything and the walker looked alright: it had not somersaulted. That was the mystery. How did Esther get out of the walker?
Based on our analysis, I reckon that she must have used her foot against the side cross-bar and with the side or the walker as the pivot, she did a somersault out of the walker. This can be possible since her upper body is well above the side. We did not make the walker too high in order that she will not tiptoe.
After that mystery, we have kept the walker since it might impede her walking development and of course to further prevent more surprises.