First of all, she may be in love. This sentence is an expression of love for the other half and a promise that she will always be with him and there will be no one else. It means that she loves the other half deeply. Of course, this other half may not be an entity, but an idol or some fictional characters.

The second is her attitude towards love. It is an expectation for the future, hoping to have a love that will hold your hand and grow old with your son. It also shows the attitude that you want more than you want. I don't want to start a relationship casually. I hope to meet people who like each other. I hope the other half will go hand in hand because of love rather than other reasons, so if I don't meet that person, I would rather die alone.

Both possibilities show that this is a very affectionate girl and deserves to be treated well. If the object is her boyfriend, please treat her well.