Getting "bulky" from lifting is one of the most common training myths out there. I'd personally like to thank media from the 80's, and even earlier, for teaching women that being small and dainty is how you win at life.
First things first, getting "bulky" is extremely challenging for women to achieve naturally due to hormones, specifically testosterone. Men have 15-20 times the amount of testosterone that women have (PMID: 30010735). Although things like training consistency and programming, nutrition, and genetics play a role in muscle growth and strength, the lack of naturally occurring testosterone in women makes it difficult, dare I say impossible, to become "bulky".
Now that we understand women aren't going to naturally get "bulky", let's talk about sarcopenia and getting frail.
Sarcopenia is the loss of muscle mass and strength that comes with age. This occurs mostly due to lack of muscle use and poor nutrition, including low protein intake, low calorie intake, and/or high calorie intake. Beginning in your 30s and 40s, you will begin to lose muscle mass and strength every decade and even up to 50% of loss by the age of 80 if you don't take measures to prevent it (PMID: 22955023).
Aging is inevitable. We do not have control over that. You do have control over how you age.
If you want to continue to play with your kids and future grandkids, move more easily with less likelihood of falling as you age, and avoid getting frail, resistance training is an absolute must. Resistance training is the way to continue to maintain and gain muscle mass as you age. Reap the benefits by completing 2 sessions per week.
Proper nutrition also plays a role, so it's necessary to ensure your calorie intake and protein intake support your life and activity. In general, aim for 1.2-1.8g of protein per kg of bodyweight.
150 lb person = 68.2 kg person
Protein goal: 82-123g
Remember, it's never too late to start training and fueling properly.
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