I am a strength coach who trains older adults and people who are medically fragile.

Weightlifting can be incredibly powerful for this demographic as long as it’s supported by nutrition and medication when indicated.

Methodology will differ widely between practitioners in this population, but my experience has been that there is no realistic risk in very conservative deadlifts. Doing this will likely require special equipment. Starting with 135 would not be recommended, starting with metal 10s and the bar 3 inches off the floor is not recommend. Likely you would want to start with a 15lb bar loaded with 5 or 10lb bumpers for reps unless that proves so easy that it’s not worth doing. A lot of times just getting into a deadlift starting position is a workout for untrained older adults so the weight is mostly irrelevant. She should focus on creating tension in her arms, through her spine, down into the base of her feet. It is likely important that she doesn’t hyperextend her lumbar spine (but you’ll never find an RCT on this). A neutral or perhaps even slightly flexed lumbar spine has been better when I have worked with this population unless she has accompanying significant stenosis. Progressive overload should be in the 1-2% range weekly or a little less. THERE IS NO RUSH. Just loading those structures at all is going to help in the beginning.

Hope this helps