That sounds like really positive new and I love the idea for making use of the recliner in that way.
She is able to make sounds in her sing song way so the vocals are there. A bit like a baby prior to their first words/speech. Think about that ManjiB; do you have any experience around babies and helping with teaching them how to say words? Why not try getting her try pronouncing the vowels A, E, I, O, U, and maybe even V and W.
Maybe encourage her to sing along to her favourite music.
And something else I forgot to mention last. As an alternative to @pando’s suggestion of the electric toothbrush inside her mouth. Why not just try use one initially to run all over her face like a relaxing facial massage…just stay away from her nose. But cover the forehead, cheekbones, around the mouth. Who knows where that might lead over time 
Not that she really needs it being PEG fed, the saliva in her mouth will be keeping that clean anyway. Saliva has magic healing and cleaning powers, how do think any oral injuries heal up so much quicker than say a cut or scrape on your arm 
Some leg strengthening exercises she can do sitting…if you don’t already know
A mini exercise ball to squeeze between her knees, for strengthening inner thigh muscles.
And a resistance band to loop around her knees or ankles to stretch out the way…for strengthening outer thigh muscles.
All beneficial for standing
The thing is to never lose hope. There will be days when you wonder if she’s back sliding. Those are the days the brain needs to process and reboot. I’ve had 4yrs of it now, you take a day or two off or do something different and when you back you may even find a little further progress.
I’m going to start a new post of videos with of simple fun activities for the elderly I’ve seen online. They’re all both physically and mentally beneficial without it having to feel like another physio exercise. The carers as well as the stroke survivors need regular breaks and a laugh.
I hope you’ll find them useful
Lorraine
Stroke Improvement Group