You are on the right track -- another sofa or loveseat placed across from the chairs should do it. Nice room!

Hmm. I might try an armchair + ottoman angled toward the TV, the ottoman would double as a seat when you have guests. I'm just not a fan of the sofa+loveseat combo.

A sofa, love seat and two chairs work very well, especially when you have children in the mix. I would put a love seat or another couch where you now have the chairs, and put the chairs on the opposite side.. You can move your existing couch further back to fit in the other couch or find a couch that is shorter than this one but one that can also be slip-covered so that it doesn't look odd.

How about a chaise at the end of your sofa across from chairs?

From Wayfair:

I like an idea with two chairs.

Two chairs with arms and no skirting, don't do armless chairs because they are not comfortable.

You can add one upholstered chair, but if you switch the location with the bamboo chairs on the other side, you can add two upholstered chairs. You just don't want a large white barrier when you enter the room.

I love your chairs! Could you please tell me where you purchased them?

I love Serena and Lily...I wish they were in Canada.

Initially I was opposed to the idea of incorporating a pouf as furniture in a living room. However, especially if some of your guests are kids, a couple of poufs might work and are low to the ground.

I would also recommend against a chaise lounge/daybed. In my experience they are rarely actually used (although the kids might have fun climbing on them). This type of furniture was originally known as a fainting couch and developed in the 19th century when women were thought to be prone to fainting due to excessively tight corsets or excessive anxiety. The daybed is sexist in its origins and most often used today when staging a home to sell it or photograph for a feature article. It would be awkward to have adults sitting on the couch and the two chairs while one adult was lying on his back or side. Then again, to each his own.