Lucy Hearfilia Guild Master

What if Lucy Hearfilia during the S-class trials was left at the guild alone to 'hold the fort' as they say until the everybody in the gild returned. And so she stayed behind, but when agnologia attacked tenrou island somehow she could sense that they were in danger. She casts a long range spell, that her mother gave her. But tenrou island still disappeared, the affects of the spell causes her to become immortal until the return of her guild mates. Lucy becomes master of fairy tail, and becomes stronger. And a few children join the guild. What will happen when everyone comes back, or will they be forever be lost.
disclaimer: I DO NOT OWN FAIRY TAIL duh