Believe me lots of people aren't smug about stuff like that! We were very lucky that my husband's parents sold an investment property and gave him his inheritance early which was a decent chunk of a nice house and I don't feel one bit smug, I actually feel embarrassed about it. I haven't even told friends we're moving because some of them have been struggling financially and don't want to feel like I'm rubbing it in. I guess it helps that I grew up with very little and have always worked my arse off so I appreciate stuff more.
That's a completely different situation though.
Ailbhe has the smug, comfortable air of a wan who has never wanted for anything! Her total acceptance of this lifestyle and the fact she appears to take it for granted is arguably fair enough, but the fact she's also happy to accept and actively chase down freebies from brands when she's in that enviable financial situation, rubs people up the wrong way.
Having said that, I was surprised to see that Ailbhe has a few years experience working for various companies, mostly abroad: I assumed she'd walked straight into the family business.
(Sidenote: I'm sure your friends would be delighted for you in your current situation - don't be one bit embarrassed at your good fortune! That said, there's no need to mention your husband's inheritance if it makes you feel uncomfortable - as you point out, it's simply an advance on what he'd be getting anyway, but at the time when ye can really make use of it!)