Is 15kg max weight to carry or can this go beyond 15kg? My baby is 3.5years old and weighs 21kg. Can the stroller accomodate her weight?
I would absolutely say that even if it could accommodate more than 15 kg (+ 2-5 in the basket), the seat is very slanted and small. There's no way you would fit a 3.5 years old weighing 21 kg in this seat comfortably. Also good to add here is that the buggy itself is quite simple and wobbly, so it is not sturdy enough for such an overload.
I recommend going for something substantailly larger, and if it has to be an ultra-compact stroller, it at lest has to be a higher-quality (therefore, more expensive than this) and with a much taller seatback.