Elderly mother cannot bear to have water on her face when doing her hair, unable to sit backwards, need something similar to what use on young children, she has to have oxygen 24 hrs day so makes difficult, always says cannot breathe if water gets on her face..
In the hospital they have shampoo in a bag. It's like a shower cap. You heat it in the microwave and place it over the hair, tuck the hair up under it, then with your hands move the bag around so you get all the hair clean. There's no water involved. However, I don't know if these are for sale anywhere. I haven't seen them at Walgreens but you might want to check a private pharmacy. I've never seen any of my patients use them in the home either so I don't know if they're available to the general public. If not they should be. Check the internet.
Necessity being the mother of invention, I've seen shampoos this way: Put the person in a recliner reclined back as far as the chair will go. Place a bath towel across the chest. Take a kitchen-size garbage bag and place it under the person's neck so that it's practically under their upper back. Have pitchers of water available and rinse the hair. The garbage bags should be placed so that the water drains into it. Shampoo. Rinse. If done correctly all of the soapy water drains into the garbage bag. But the recliner has to recline very far back so gravity does it job otherwise you'll have a garbage bag filled with water that wants to slip down and will get water all over the floor. This is very effective in a hospital bed as the entire bed will tilt back at a 45 degree angle and the person will be practically upside down. But with the right recliner it can also be done.
Some people will say dry shampoo but all dry shampoo does is soak up the oil. It doesn't actually clean the hair.
If you have a detachable shower head you can use that and give your mom a towel to hold over her face. Have her hang her head down. A shampoo takes just a couple of minutes so your mom won't be in distress very long and you and I both know that she can actually breathe if water happens to get on her face but holding a towel to her face should keep the water from spraying her in the face.
Good luck!