When a property is originally unified and then split, to oversimplify somewhat, any existing utilities, sewer lines, etc. receive an "easement" or right to continue as is--she does not need to reroute them. You bought a property that had those lines in place; you have no right to now demand more than you bought and require them off your land.If they leak and damage your land, you could sue her for any remediation, etc. costs--she is responsible for maintaining her lines and any damage, harm, etc. they do.