You tell me what salary you need to gross, in order to net 10-11k a month. Then tell me where it is on the BA pay scale. It's pretty high up on the one that I'm looking at. If you prefer, you can give me a years of service estimate instead. 'Senior' is a subjective term, after all.
In my circumstance (married without kids), it's north of £200k. Please point out where you believe I was 'fibbing'.
The salary on a normal month of flying a is about £10500 including duty pay and HKPA, but excluding allowances and 13th month/12 if you get it.
I typically got about £600-700 in allowances, and pro-rata 13th month is 750. So, if you expect 13th month, add 1400 to that figure above. Call it £12,000 to make the maths easy. Tax depends on your circumstance, but I paid about 11% this year.
I'll leave it to you to decide if it's enough. I'm providing facts and nothing else.