Hi Kate
It is advisable to get advice on trade mark from an
intellectual property lawyer. When registering a trade mark, IP Australia will perform an examination process where the trade mark you wish to register is reviewed against other marks on the register. If IP Australia are satisfied there are no competiting marks, they will then be an objection period where the public may object to the registration of your mark. If the That's So Emily does not have a registered trade mark, they may still oppose the trade mark through
IP Australia if they have a reputation in the market - this is known as a common law trade mark.
If "That's So Emily" opposes your trade mark, then that brand must give reasons in an objection notice. They will consider the grounds for objection. As you mentioned, if "That's So Emily" is similar to the mark, then IPA will consider whether it is likely to cause confusion of the public between the brands. IPA will also consider whether the marks phonetically (sound) the same.
Consideration needs to be also given to whether marks (logo designs) appear the same or have central aspects of the design that appear the same.
I have a blog with content on
trade mark registration process in Australia. You're welcome to check it out.
Hope that helps
Ben