3 weeks ago, we adopted 2 male kittens who are now 3 months old. They stayed in one room for a couple of weeks until they got over respiratory infections and they've had the run of the house for 6 days now. They have met our 3-year-old female cat, who has kept her distance (hissing and moaning, of coarse) on countertops and tables that the kittens can't access. This cat had her brother and sister for companions until 6 months ago, when we lost them to leukemia, so she has shared the house with other cats before. Lately, she's been feeling more comfortable (but not TOO comfortable) and has been coming down to the floor. The scary part is that the kittens have no fear of her and are trying to walk right up to her. I always intervene and scoop up each kitten as he gets too close. I have no idea what she might do. Does anyone have advice on this? Am I handling it the right way?