Yup, Ella does it when she gets very worked up.
She's done it ever since she was tiny, but thankfully it has gotten less as she's got older.
We had one the day before yesterday when she shut her fingers in a door. She held her breath until she passed out and came round a moment later.
It is very scary to see isn't it, especially as your girl is so very tiny!
My mum told me my sister used to do it too, and to make her take a breath when she saw it coming, she'd blow in her face quickly and strongly, like a big sudden puff of air.
It works most of the time with Ella too.
Also, thankfully when they do pass out, they immediately start breathing again.
Hope this helps chicky!