What primary historical sources do we have that mention the goddess Eostre?
The first month, which the Latins call January, is Giuli; February is called Solmonath; March Hrethmonath; April, Eosturmonath […] Eosturmonath has a name which is now translated ‘Paschal month’ and which was once called after a goddess of theirs named Eostre, in whose honour feasts were celebrated in that month. Now they designate that Paschal season by her name, calling the joys of the new rite by the time-honoured name of the old observance.[4] That’s it. Bede doesn’t describe the goddess. He doesn’t say anything about the feasts that were held for her. He certainly doesn’t mention hares or eggs.