Need help! Can’t get into anything but 3rd & 4th gear (& reverse).

Looking for help to diagnose a shifter issue. Yesterday wife was on the way home from work and found she couldn’t downshift into 2nd and had to limp home in 3rd gear a few miles away. Feels like something with the shifter, but hoping to get some help on what to look for and what we can repair ourselves. Will be digging into this later this evening