Is it suitable for children aged 3 and a half to wear sneakers?

3 years old, you don't need to wear particularly soft shoes. Wearing sports shoes with a little hardness around them can play a role in fixing your feet. It's not that the softer the shoes, the better the soles. However, you need to add some rubber. Because you need to bring non-slip children, you'd better go to a physical store to buy some brands of shoes. It's ok to wear wide cloth shoes when the weather is hot now.