I'll bet all that 'guilt' you are feeling 'belongs' to your niece and your sister and is all mixed in with your overbearing mum Peri.... family dynamics can be very messy and leave lots of hurt. As some above have said, being honest with her can maybe help you get rid of that 'guilt' once and for all. I guess its better to face up to it, than to leave it all to fester longer. Good luck...let us know how it goes. x