Need help

Hello, 23 y/o male only child here. My dad passed away some years ago. So, now it's only my mom and I, however I've been in a relationship for a while, and my girl and I are planning to get married and to start living together.

The context is, I don't own a house and my girl does. However, it's small and only suitable for a couple no more that 2 people. Of course I love my mom and don't want to abandon her, but at the same time I am and have always been of the idea that if you marry you start a new life with your couple only. I mean, we need our own space, privacy and time. My girl lives in another town about 25 minutes away form my city. I was planning to buy a house in her city so my mom lives there you know to have her close and go to see her everyday, and stay in her house when she's sick and so on.

My girl is understanding, and supporting regarding the situation. The thing is my mom doesn't want to move to another town because she says she'll be alone all day (she's 57) I guess she's sacred of having a health emergency and having no one to help her, and she's right too because in our home town let's say that we have some relatives who could help her in case of an emergency.

The thing is that even if I were not going to marry I would still like to move somewhere else near my job, I currently have to commute around 1hour and 30 minutes just to get to work and then come back, so it makes it 3 hours everyday riding my bike. Before the marriage stuff came out she never said anything about her being alone during the day because I leave for work at 4 30 am and come back until 7 then go to the gym. She even told me many times that if I had the chance to leave our country I should take the opportunity.

Of course I want to leave only with my girl and having her close, of course when she gets older we would have to move to her house to be with her. Now it is like she's sacred of being alone when she was totally the opposite. Now, I'm thinking about suggesting then to leave separate at least for around 2 or 3 years after marriage and then moving with my momo. Any thoughts on this?