Think that getting TRVs for your children will be very difficult given that you don’t have savings.  Getting a TRV on your own will likely be difficult enough.  As visitors your children won’t qualify for free education or healthcare so that would also be a huge issue.  Think you should start with trying to get a TRV first and not get too ahead of yourself.  Has your partner visited you in person numerous times?  How long have you spent together in person?