The girl was found by police in a property in Sidegate Lane just after 11.45am on June 30.
Formal identification procedures have not yet taken place.
Scott Jeff, 22, and Chelsea Gleason-Mitchell, 22, both of no fixed address and formerly of Bedfordshire, have been charged with murder after being arrested in Bury St Edmunds on July 1.
They have been remanded in custody and are due to appear at Ipswich Magistrates’ Court on Wednesday.
A mandatory referral has been made to the Independent Office for Police Conduct regarding previous police contact with the deceased elsewhere, the force said.
Detectives are continuing to appeal for anyone with information about the incident to contact the Major Investigation Team at https://mipp.police.uk/operation/363723O42-PO1 or by calling 101 quoting crime reference 37/37749/23.
Alternatively, contact the independent charity Crimestoppers on 0800 555111 or at crimestoppers-uk.org