You have some pics of the crew? If you meant to post them, they aren't attached yet. :D

Sorry

i

The following buffs/debuffs helped me to beat the Nether Spider: 

• heal reduction. Unlike the Dungeon Spider the Nether Spider is not immune to that debuff, if it's put on her, you can just attack and kill the small spiderlings. Coldheart could work, if she is at lvl 60.
• remove debuffs. Block debuffs doesn't work, the poison is unblockable, you need at least one, better more debuff removers. Mausoleum Mage with his A3 is one option. I personally used Reliquary Tender, she is really the MVP at Nether Spider, with a remove debuffs on a 2 turn cooldown. I don't see that champ at your account. Maybe you have more debuff removers in addition to Mausoleum Mage.
• remove buffs. Take away the counterattack buff from the Spiderlings. I see Madame, she can do that job.

Thanks.

Skadi is right, except I'd recommend Sethallia over Serris for the buff stripping job, because Sethallia will also do a cleanse (though single target) and heal, plus a chance of HP burn with her A1 that will help take the spider down faster. And last but not least, Sethallia's buff strip is on a 3 turn CD if booked, 4 if not, while Serris' is on a 4 turn CD at best. Those 4 turns may be too long to immediately strip the spiderlings' buffs each time. Though if your Sethallia isn't booked, guess it's 4 turns either way. 

Are working on Drexthar fragments?  Mine can solo Nether Spider all the way through Hard.

Farm Spirithost from campaign, get her to level 50, give her survival gear and youre golden. Worked for me.