Watch the video report by ITV Wales reporter Mike Griffiths
First Minister Mark Drakeford has called for caution as schools across Wales welcome the youngest children back to the classroom.
Foundation age children - those aged between three and seven - begin a phased return on Monday, having been away from the classroom since mid-December when schools were closed in a bid to reign in rising infection rates.
All primary school pupils, as well as older age groups in years 11 and 13 who have exams, could return from March 15 if the country's public health situation continues to improve.
The coronavirus incidence rate in Wales is currently 83 cases per 100,000 people - the lowest of the four UK nations.
Kirsty Williams told a press conference, "Where possible, we also want to give some flexibility around other learners, such as Year 12 and those in Year 10 who may also have been entered into qualifications this summer."
"Unfortunately, for those learners in secondary settings or colleges, this won't necessarily be a return to full-time on-site learning."
Ms Williams said the situation for other students would be confirmed before the Easter holidays.
"But I can tell you now that my preference is to get all learners back in school after the break," she added.
Ms Williams also confirmed coronavirus testing will be rolled out to Years 11 and 13 to help with the return of older pupils from 15 March.
At Aberbargoed Primary School, pupils were ex
cited to get back into the classroom on Monday morning.
Headteacher David Lewis told ITV News, "School buildings are fairly soulless places without children they are what makes our school community so it's great to see them back.
"We'll be continuing with all the mitigating actions that we've had in place over the last year. Face coverings, social distancing, hand sanitiser, frequent cleaning throughout the day, separate entrances and segregated play areas.
"It's really important that people remember although schools are open, the rest of the community is still very vulnerable and until we've all had that vaccine, we still need to be as cautious as ever."
Mr Drakeford warned that this latest easing of Wales' coronavirus lockdown restrictions was not an excuse to socialise at the school gates.
"Please don't congregate at the school gate. Please don't think it's a reason to go and have a cup of coffee with people afterwards," he said.
The plan for a wider return has been met with scepticism by the NAHT Cymru teaching union, which has cautioned against working towards an "arbitrary date".
A spokesperson said: "It is important that we continue to be guided by the science rather than getting stuck on one particular arbitrary date.
"We all want to see all children back in school as soon as it is safe, but that return has to be sustainable, with a proper plan to minimise continued disruption to children’s education going forward.
"At the moment, certain aspects of the operational guidance on measures such as bubbles, face covering, social distancing are vague at best."
The Welsh Government has said it is providing an additional £5m to schools, colleges and local authorities for new face coverings and to invest further in items they need to keep their premises safe.
Not all foundation phase schoolchildren will be returning to the classroom on Monday due to higher coronavirus infection levels in parts of the country.
In Wrexham, where cases have recently been markedly higher than other parts of Wales, schoolchildren will not return to school until Friday at the earliest.
The council said it was taking a careful approach to reopening schools.
Councillor Phil Wynn, Wrexham Council’s lead member for education, said, "Coronavirus levels have been much worse in Wrexham compared to many other parts of Wales in recent weeks, so this is a cautious approach we’re taking.
"We’ll monitor the local situation continually, and will work with schools to review and finalise arrangements after half-term.
"Foundation phase learners will not return until February 26 at the very earliest, and headteachers will keep parents fully informed.
"It’s all about helping to keep people safe, and the wellbeing of our pupils, staff, parents, carers and wider communities is our priority."
At Friday's Government press briefing, which was also an update of the administration's three-weekly lockdown review, the First Minister said there were "brighter days ahead".
"We are seeing encouraging green shoots as we move into spring, with better weather and brighter days ahead, coronavirus cases falling and our amazing vaccine roll-out continuing at pace," he said.
"We have seen, however, time and again the world over, just how quickly the situation can deteriorate in a matter of weeks. But, if we work together to keep Wales safe, we will see more elements of normal life returning."