Can you help a small migrants' rights non-profit figure out this networking issue? (Flowchart and effort included!)

Hi everyone,

I work as an assistant at a small non-profit and everything is my job.

My job today is to fix my boss' internet before she comes back. We set up an almond router as an access point because the wifi signal in her office/conference room is weak. She often experiences slower speeds and disconnecting calls, and she has suggested that I buy a new router. I think there may be another issue in our labyrinth of a network that may be causing it. I believe I have daisy chained the two routers together correctly.

Here is a flowchart of our network: https://imgur.com/a/9mYwk

Here are my questions:

1) Do you think we simply need faster internet? 2) Should I get another router to replace the almond? I would prefer a dedicated wireless access point like Ubiquiti etc. but I'm unsure whether I can plug the VOIP hardphone into those via ethernet.

I'm sorry if these questions are juvenile or if it doesn't seem like I did enough homework. I would really appreciate any help that you may have to offer.

Thanks so much!