I'm just thinking out loud here.
I wonder if there's any advantage in waiting until she is a British Citizen? Then she'd be eligible to change her name by UK Deed Poll. These papers are recognised by all UK government departments, and organisations, as well as by all British Embassies and High Commissions anywhere in the world.
Also by the Passport Service, DVLA, Local Councils, Electoral Roll, Banks, Credit Cards etc.
Of course Birth Certificates cannot be changed.
I'm not sure if there are any age restrictions.
Food for thought anyway.