Problem with image & header text being responsive to mobile screen

I recently realised that the subheader images i have uploaded on my webpages are not responsive to mobile screen. All the images don't resize proportionately even though i have set the Responsiveness to ON in the Betheme options.

Also, i noticed the header text tend to overlap when view on mobile screen if its long. I have tried to adjust by changing the line height in the betheme option but it tends to change throughout the pages. How can I limit the changes just to one page? My other pages seem okay.

Please advise what i should do to make my subheader images respond/resize to mobile screen and resolve text overlap

Example of subheader image not resized to mobile screen: (You can see that the woman's totally cut off and only part of her head can be seen in mobile screen)

Greatly appreciate any one who can help me with this, especially the images! As I have many pages to fix!

Thank you so much!