I don't think that it's Layla.... But your (animefan12blast) idea might be true. But for some reasons, i still think that it can't be Layla.
First of all, if the hood person is Layla, she is supposed to cry in Lucy's Debut match, and not in Natsu's debut Match. Next is that if she is Layla, she must has the same magic as Zeref and that means that Lucy could also have the same magic as Zeref because Lucy is Layla's Daughter. And one another thing is that Lucy's Father told lucy that Layla's grave was moved to somewhere (sorry i forgot where it moved to) that might means that the corpse of Layla is already identified.
But it's just my Theory, and i guess it can be someone Jellal know because he seems to be surprised after he saw her face.
Let's just wait for the next chapter while having our guess in mind ',' :3 ^^