Firstly, child passports are valid for 5 years, not 10.
Immigration officials are unlikely to regard your daughter as a terrorist or illegal immigrant and there's no need to change the photograph on her passport. This is from the website of the Identity & Passport Service:
"We know that a baby�s appearance changes quickly, but separate passports have been successfully issued to babies and young children for many years without there being any problems about the child�s identity or appearance. However, you can if you wish change the photograph during the five-year life of the passport, although this is not necessary".
Source:
http://www.passport.gov.uk/apply-photos-babies .asp
Chris