It really depends on the child how much practice they get and how developed their fine motor skills are. Most children at my nursery school begin tracing around three and by 4 usually can write their names. If you want to start teaching your little girl make dots to form the letters in her name and have her follow the dots to write her name. Also dotted lines are a good way to start, and wavy lines with dots so they can follow and trace. There are many books you can get that reinforce writing skills. Three and a half is young but not impossible. Also start with fat pencils they are easier to grip then regular #2. If you have a school supply store near your home you can purchase some great materials to help her learn. Lakeshore Learning has a few locations or you can go online and purchase.