But Thomson said it did not go far enough and initiated the proposed submission to the Remuneration Authority to make changes so councillors would not be discriminated by choosing to use family members.
The submission also asks for the criteria to ensure elected members who are grandparents and provide the day-to-day care of their grandchildren or adopted whānau are also eligible.
Thomson said she had spoken with elected members around the country and the feedback was many parents couldn't access the current allowance.
"It seemed very backwards and inequitable. I think we are now moving towards a place in society where we recognise we can't just rely on family members as carers expecting them to have unlimited time and resources to do that care and not reimburse them."
Her mother predominantly looked after her son while she was on council business so she would likely use the allowance as it was unfair to expect her to do it for free, she said.
Thomson said elected members' schedules weren't always predictable and agreed this could also be another barrier to parents entering local government.
When asked whether the salary should be coming out of her own $92,500 councillor salary, Thomson said it came down to the purpose of the existing policy which was to remove barriers for people wanting to stand for local government and promote diversity.
"It's actually a very small cost which for a lot of people will make a difference and make it more of a viable option for them to run for council or put their name forward."
However, in an oversight, Thomson's own council has not even adopted the policy - despite supporting its introduction - and is being asked to sign it off on a temporary basis on Thursday so it can approve pending claims for 2020/21 estimated to be less than $6000.
But staff have warned that if its planned submission to the Remuneration Authority is successful then it could cost ratepayers more in future years.
Along with Thomson, fellow Hamilton councillor Kesh Naidoo-Rauf had her second child last year while also on council.
Hamilton mayor Paula Southgate said she supported the proposal in principle but it still needed to be signed off by the council.
A number of councils had already agreed to pay an allowance for childcare and Hamilton was just catching up, she said.
"When people have costs to cover or are taking time off other paid activities then it seems reasonable that there should be some support for them."
Southgate said while councillors were paid well, people did need to remember that they were self-employed and had other expenses.
"Other people do have to pay for their own childcare depending on the policies of the organisation but they may also get contribution to KiwiSaver, have their ACC levies paid and so forth."