If every day looked like today…

First... what is your timeframe for losing the weight? Second, what is your starting point, i.e. what is your current weight?

Getting older per se isn't a big factor. (I'm 67, F.) If our life routines are less active (daily life stuff) or our muscle mass has declined, that can create some issues.

You seem hesitant to say how much you actually weigh now, which makes advice difficult. Generally, a good goal is to lose no more than 0.5-1% of current weight per week, with a bias toward the lower end of that. If 15 pounds is all you have to lose in total, 0.5 pounds a week would be a good goal. (There are reasons why it's a good plan to lose more slowly as we have less fat to lose.)

For most people, unless severely obese and under medical supervision to prevent complications or deficiencies, around a pound a week is a perfectly good weight loss rate. Misery via low intake doesn't contribute well to staying the course long enough to lose a meaningful total amount of weight. 4.6 pounds in 5 weeks is pretty darned close to that pound a week idea.

Besides that: The 5 weeks projection is pretty much useless. Read the full text: "If every day were like today". Every day will not be like today. How much you move in daily life matters, exercise matters (and the calorie estimates can be imprecise), sometimes we sleep/rest more, blah, blah, blah.

On top of that, the prediction assumes you're exactly statistically average in your calorie needs. Odds are you're close to average - most people are, by definition - but probably not exact. (MFP guesses 25-30% off for me, which is rare, but possible.)

If you're looking for a reason to throw in the towel, the dumb 5-week projection is as good an excuse as any. But I'm guessing you don't want to throw in the towel. You probably want to succeed.

Best odds of that are to stick close to your calorie goal for 4-6 weeks, then adjust your calorie goal based on your real-life average weekly results. To do that, assume 500 calories a day is a pound a week, and do arithmetic for fractional pounds. Shoot for that 0.5% of current weight per week or thereabouts, and find/practice the routine habits you'll need to stay at a healthy weight long term almost on autopilot.

That works pretty well, IME. I was a little younger than you (59-60) when I lost from class 1 obese to a healthy weight, after about 30 years previous to that of overweight/obesity. I've stayed at a healthy weight for 7+ years since, pretty much as described above. Maybe that won't work for you - I don't think there's a universal perfect solution - but that's why I'm suggesting what I did above.

I wish you much success . . . it will take patience and persistence. Best wishes!