Dr Ho served as Director-General of Education from 2009 until her retirement in 2015. During her tenure, she played a key role in establishing the ethos of the teaching profession and the setting up of teachers' academies to foster a greater teacher identity and promote teacher growth. A strong advocate of the bilingual policy, she led in the review of the mother tongue curricula. She also secured the STELLAR programme to provide all primary school pupils a strong foundation in the English Language.

Dr Ho championed the teaching of character and citizenship education and advocated the inclusion of 21st century competencies in the school curriculum. She gave close guidance to the setting up of MOE's kindergartens, first opened in 2014. Dr Ho was appointed to the first Lifelong Learning Council in 2014 and played an active role in championing lifelong learning in the community.

Since 2015, Dr Ho served as MOE Advisor overseeing a number of organisations such as the Singapore Examinations & Assessment Board and the National Institute of Education International (NIEI). She was conferred the honorary degree of Doctor of Education by the Nanyang Technological University in 2023, before her second retirement in 2024.