This worked. She didn't cry on the following day, and they both got a new bubble gun from the toy shop.
These bubble guns have better design and a few advantages. The solution bottle can be screwed tight to the gun, so that there was no dripping on the floor and caused no waste on the solution too. They are easy to be handled by the children.
The disadvantages of these bubble guns were consuming to much of batteries and too much of solution. Thus, we need to have a lot of batteries and bubbles solution standing by at home.
Another update which is not relevant to the title of the blog. I actually keep track of May and April's growth chart constantly. April is showing a positive result in her growth, but May isn't that good. Her weight is stagnant for about a year. We only noticed her growing taller, but no change in her size so far. I wasn't that worried at first, as she drank 3 times milk and ate 2 times main meals regularly. Nevertheless, there were some people making a remark on her skinny body lately. May be she is getting taller, or may be due to the lack of sleep in the morning after going to school, she looks significantly thin now. I couldn't relax and feel no pressure anymore. We bought a small tin of Pediasure, and started to let her take it as her night time feeding. She managed to finish the 200ml (5 scoops of Pediasure) on the first night. Her milk bottle was still on the sink at the back. We really hope to see her gaining some weight soon.