You have a wonderful mom. She raised you, gave her soul, always did everything only for you. And I forgot about myself. So she did not have a relationship with men. Now you want to restore justice, make your mother happy and find her a husband.
Of course, you should start your searches with dating sites that are popular today. You know your mother well, her tastes, hobbies, wishes. Therefore, you can search for yourself, even at first and without devoting it to your activities. If potential suitors are interested in her profile, try to get to know them better by correspondence. Having figured it out, you will identify several, in your opinion, worthy, and then, having chosen the right moment, talk to your mother. Provide her with the results of your searches.
If she doesn't mind, show her all the candidates and then hand the correspondence into her hands. Let her talk to them. It is very likely that among the chosen candidates there will be one who will really touch her soul, and in the future they will be able to unite their destinies.
Another option for finding a husband for a mother is polling her girlfriends. Maybe just one of them will have a lonely relative who is not averse to meeting an interesting woman in order to create a family. Talk to her about the possibility of dating, how to create such a natural situation in order to introduce mom to a man. After all, at their age it should look pretty natural. Perhaps gather with your mother for an exhibition, and there "by chance" you will meet a friend who, allegedly, brought her relative to meet the beautiful. Or you can even organize such a meeting in the park.
Alternatively, take a closer look at single men from neighboring entrances. Your mother is a busy person, constantly at work, she does not know her housemates. And you can ask about those who came to your attention, the neighbor's grandmother, who sits on a bench all day and, of course, is aware of all events.
If such options do not suit you, then there is another one. It's pretty potent. Take your mom a voucher to any sanatorium or holiday home, which is located near your city. First, study all its advantages. The main thing is that this is not a youth party boarding house, but a solid rest house, where she will spend several days surrounded by people of the same age. Even if she does not meet her fate there, then just communication and the beauty of nature will give her a lot of positive emotions.