Short, trying to gain muscle and lose fat

Women gain muscle very slowly, and that is when they are lifting heavy3-5 days a week, eating enough protein, and bulking.
When eating at a deficit it is even slower (Read nigh on impossible), but lifting with no actual gain does preserve muscle while losing, and improves ones strength.

Has your trainer got you on a progressive overload programme?
Are you eating back at least a portion of your exercise calories to help fuel your workouts?
Sticking to your basic calories of 1300 could have you either moving less in your daily activity which will lower your NEAT or, have you under performing in the gym. Neither are ideal and both could cause problems in the long term.

As far as not losing like you expect at 1300 cals. Have you recalculated your calorie needs lately (1300 does sound correct for your stats) and do you use a digital food scale to weigh all your food?

Tightening up your logging and double checking your entries against the USDA data base or the package label will help with precision.

At the weight you are at .5 lbs a week would be a good weekly deficit goal as you have little fat to lose.

Try and get ~.8g of protein, helps muscles and bones, and .3-.4g fat per lbs of ideal bodyweight, the rest of your calories fill in with carbs. ( your macros, 40/30/30, should have you close to those numbers)

If you haven't had a check up lately it may be worth having one. Checking for thyroid, t2 diabetes, high blood pressure, and cholesterol and getting them under control, if needed, can help with weight management.

Unfortunately, because you are at a healthy weight, post menopausal, and short, is just going to be slow. It can be done though so don't give up.

I didn't and at 63 I am lifting heavy x3 a week and working on a very slow recomposition.

Cheers, h.

Wine has 3 servings of fruit per glass.

If you ask about eating back exercise make sure you mention that MFP is set up for a deficit without exercise and your calorie allotment by the app reflects that.