A blaze broke out at around 3.30pm on Tuesday in Pegasus Road, in the Blackbird Leys area.
Seven children and three staff members were inside the building at the time but were uninjured.
Ten fire engines were called to St Mary's Street on Tuesday afternoon.
The woman was retrieved by firefighters who then administered emergency care and used a defibrillator to try and resuscitate her.
Around 100 firefighters are tackling a blaze at a thatched property in Cranborne.
More than 200 firefighters tackled the blaze at its height, which broke out on Tuesday on Walworth Industrial Estate.
A huge fire at a grocery warehouse in Andover is still burning two days on. A one mile cordon has been put in place.
Steve Apter has been in command at incidents including the Westminster Bridge terror attack and the aftermath of Grenfell Tower.
More than 50 firefighters tackled the blaze near Waterlooville on Wednesday afternoon.
Hampshire Fire and Rescue sent eight fire engines plus an aerial ladder to the scene in Sheepwash Lane.