I have interviewed and hired older workers and have worked with older workers in all of my previous companies. Age discriminatin is a real thing, and yet someone hired those older workers, so it's not an insurmountable thing. You often hear things like "well, you need to keep constantly learning new things", which is true, but older workers don't need to pretend to be younger workers as they have their own advantages and disadvantages, and are better off pushing their advantages than insisting they don't have disadvantages. The advantages of older workers are:
* better judgement, more emotionally mature, more likely to see projects through to completion, more likely to stay at the firm longer. Play up to the advantages. Assuming these are, in fact, actual advantages of this person.

Also, be aware of the overall climate. She should be able to land a dev job in the current climate where standards are being so dramatically lowered and people are getting promotions/raises merely because of the tightness of the labor market. This is a seller's market - just the right time to jump in, regardless of your age.

My main advice would be the same advice I give to everyone else:

* Don't lie on your resume. It's OK to say "I can pick up skill X because it's similar to skill Y which I already have" or "I didn't use X at my last job, but it is similar to Y and I've been brushing up on this as more people need it" (assuming you have been learning X on your own time). But don't say you know skill X if you don't. Don't wing stuff.

* Read the requirements of the job posting and spend some time trying to understand this problem space and company. Really think about the things they need, and then study up on and practice these things.

* Adopt the attitude that you are there to help them solve problems in exchange for money. So try to be helpful and have appropriate expectations of compensation commensurate with the value you add. Do not adopt the attitude that this is some kind of courtship and they need to woo you, or if they turn you down that you have been personally rejected, or that you have a career arc and they are there to boost you along the arc. The job will not give you meaning, it will not save your soul, it is an exchange of your problem solving skills for money. It may well help your career arc, but that's not going to land you the job.

* Do not hop from job to job, and be prepared to have a good explantion if you did. Be aware that it is a red flag to see a sequence of 4 one year positions at different places, because you start being really productive at the end of that first year. If that's when you look for greener pastures, the firm hiring you should dramatically downgrade the estimate of value a rental will provide as you will be leaving before the time invested in training you starts to pay off. Similarly, don't say "I really want to be a manager, and I thought this dev role was a good way to get into that". Apply for a manager job if that's what you want to do. If a firm is looking for a rental, they'll let you know. Usually they are not looking for rentals but people who will learn the tech stack and then deliver a stream of value rather than dissapearing.