The area may be a festoon, but at 4 months could still be swelling. Wait a couple more months and massage the area to reduce swelling.
If the swollen area is a festoon, then a lateral cheek lift through an extension of the lower blepharoplasty incision is the only solution. However, this is a complicated procedure, and has to be done by an experienced board certified plastic surgeon if it is going to work well and not cause complications.
Potential risks are a noticeable scar on the outside of the lower eyelid and cheek.
Another risk is ectropion, a downward pulling of the lower eyelid also called the sad eyed look. This occurs if too much skin is removed or if the eyelid support is damaged.
Frequently, this procedure requires a canthopexy to enhance support of thre lower eyelid.
If your doctor is a very experienced board certified plastic surgeon who does a lot of eyelid surgery, then this may be safe.
However, I would be very cautious and discuss these issues with your doctor.