How soon to get another horse after losing one?

This past friday My Horse snowball fell.she was in her 20's. she couldn't get up.so i got some pain MDS from vet early saturday morning gave her the MDS.then on sunday we used a backhoe to hoist her up she had no desire to move her back legs.or maybe she couldn't .the vet said they weren't broken she was just old and knew it was her time.So yesterday i had the vet put her down it was really sad.i have been crying off/on since yesterday.A friend called me today and said he has a horse that needs a good home.she's a spitting image of the one i just lost but much younger is it too soon to get another? I do want her but i am feeling guilty and very sad