Hi there, I have over 10 years of experience working with Linux and +7 working with AWS (Certified), yes you can monitor Lightsail's RAM with cloudwatch (for example) but you have to pay a bit more for that service (Cloudwatch). Lightsail is more or less the same as any other EC2 instance. I think I can help you out with this, ping me and we'll get this done. Cheers mate.