PhD in machine learning in my life? I'm 37; graduating with BA in math (online degree) this summer Title is a pretty good TLDR.

I would like to get a PhD sometime in my life.

I have a stable job where I can work from home frequently. Unless something catastrophic happens, I should be receiving my BA in mathematics this summer.

I would like to continue my education. I know of many data science and machine learning online master's degree programs that I would like to apply for.

I would love to be able to study some particular aspect of machine learning and become an actual expert in it one day. Automated machine learning comes to mind, but many other aspects fascinate me.

I'm perfectly fine being an older student at any college but there are some issues that are getting in the way of my long-term goal.

Right now I'm the main source of income for myself and my girlfriend. So I will have to wait until I am more financially stable before I could apply for a PhD program. From what I understand, most programs do not offer much income. It's going to take a couple of years of planning and sacrifices to be able to financially handle a lower income.

In the meantime, I feel that getting an online master's degree would be helpful. The problem is that almost all online degrees DO NOT OFFER A THESIS OPTION. This concerns me, since that would be the most enjoyable aspect of grad school. However, if that is my only option, I am okay with that.

Would it make sense to go to an online grad school and, when I'm financially stable, cross my fingers that a PhD program will accept a student who has only attended online classes for the past 3-5 years? From what I understand, most PhD programs want to see some research experience. Or at least have some professors that you can connect with. Going to school online prevents me from making a connection with professors, so I have doubts that I could get strong recommendation letters that way.

Questions:


What can I do with the next 3-5 years of my life to help my goals?
How can I connect with professors who I only interact with online?
Is it even possible to do quality research while working full time?
Should I wait until I'm financially stable and then apply to a physical campus for a master's program?
Are online degrees even worth it, if my ultimate goal is a PhD?
Rather than give a long answer to a long set of questions, let me propose a strategy for getting all your answers fairly quickly. Make an appointment to visit a quality university and a professor in machine learning. It might be a place you'd want to go, but it need not be. Ask him/her these questions and try to work out a plan that might lead you to success. 

I'm going to guess that online-only education will be less valued than in-person education, but by how much, I can't say. 

Yes, you can do quality research part time, but it takes a lot longer than when done full time - especially if you don't have collaborative relationships to aid you. 

The other questions (and even these) should be explored face to face with someone who can answer follow up questions and help you devise a plan. 

Note, too, that 37 is still pretty young. Ignore the age factor.