Enrollment in a lower school year

Hello,
I am planning to move in Australia soon. I have a 11 years old daughter. Her level in English is maybe A2. She is better in reading and writting than in speaking and listening. She must be in year 6 according to her birth date. I am worried that it will be very hard for her to start in the midle of the last school year of the primary school. It will not only be difficult with the language and the adaptation in a new school, new country, with no friends and etc but she will have to change it (the school) only after a few months (in January). What to you think? Has anybody experienced this situation? Do you think it is possible to enroll her in a lower year? If it is possible, do you think it will be the right decision? And last - is it very important that the school has ESL support or it is not obligatory to look for such kind of school. I will appreciate any advice. Thank you in advance!