Hi Linda and welcome to 3FC!

Congratulations on maintaining your weight loss for so many years – that’s awesome!
Boy, do I hear you on how hard it is to get rid of the pounds once we’re in our 40s (and beyond).

What seems to work best is a three-part strategy of nutrition, cardio, and weightlifting. I know you said you’re doing WW, so if you spend your Points wisely on lean proteins, good carbs, good fats, and stay away from sugar and processed diet junk food, you should have nutrition covered. Are you doing any cardio? That’s essential for burning calories. Running, walking, swimming, biking, elliptical or crosstrainer (if you have access to them) ... any of these will get your heart rate elevated and help you create a calorie deficit.
Finally, about the weights – good for you for recognizing how important resistance training is for weight loss!

About the ‘toning’ versus ‘bulking’ – honestly, there’s only muscle building. You’re either building muscle or not - it doesn’t come in different flavors, like ice cream. We women aren’t ever going to be able to build big bulky muscles like the guys because we just don’t have the hormones for it (unless you take steroids like the pro women bodybuilders do and that’s why they have that freaky big look

).
Having said that, there ARE different ways to train and some ways are designed to maximize muscle growth. If you ONLY lifted very heavy weights for very few reps (like 4 – 8), you’d be training for muscle growth. But BFL uses a different sort of plan. It's a common kind of pyramid scheme, where you start with sets at low weights and do high reps and then drop the reps as you increase the weight. It’s not going to bulk you up or make you too big. I think it’s an excellent way to achieve your goals of tightening, building strength and endurance, and building up your lean body mass.
I typically use the same kind of lifting scheme when I’m working out: a warm-up set with lower weights, and then gradually increasing the weight with fewer reps each set. I try to go to failure on most of my sets. It’s not as formal as the BFL plan, but it’s the same general idea.
Some women make the mistake of lifting too light because they’re afraid of getting too big. So they do tons of reps at low weights, which really doesn’t do much of anything for your muscles except perhaps build a little endurance. You need to
challenge your muscles with heavy weights in order for them to grow (and growing muscles is a good thing!).
In my own experience, lifting as heavy as possible has only made me smaller, not bigger. I’m a personal trainer and just about every woman who I talk to in the gym is worried that she’s going to bulk up. So my usual response is to ask them if I look bulky (I’m size 4 so I hope not!

) and then tell them that I can leg press 500#. That usually convinces them that lifting heavy won’t make you too big! Mel – another moderator here at 3FC – is one of the strongest and tiniest women you’ll ever meet. She can out lift many men but keeps getting smaller and smaller (I think she's just faaaaading away ...

) Karen (MrsJim) – another mod – weights between 145 and 150 (down 115 pounds) and is a stunning size 4 due to lifting heavy weights. Here's a recent photo she posted:
And I don’t mean to neglect the others – there are many more success stories here of women who have gotten smaller and tighter due to lifting heavy weights. So please don't worry about getting too big - it's not gonna happen!
We have a forum here at 3FC called Ladies Who Lift (LWL), right below this forum, and there’s a ton of good info there in a ‘sticky’ thread called
Basic Bodybuilding Information that you might want to check out.
Best of luck to you! It sounds like you’ve got a great plan for success.