Don't feel bad at all for having the farrier out for only one horse! I know it's a bit different over there with people 'tipping' & such, but he'll surely tell you if he's got a long way to travel & no other clients close by, so wants a bit extra for it.
Re flaring at the quarters, yes, it's not bad, just pointing it out. Re getting her feet more upright, that may be warranted if you are attempting to change a 'negative' angle on backs, *but* while those heels are crushed flat, they're too long already, so you can't do it by letting them grow more. Front feet appear(I appreciate pics may not give accurate idea) way too 'steep' when considering h/p & hairline angles.