Where exactly does Mamma Longlegs spawn?

Question

Since Spider Nest Mini World Change is on my world, I decided to make achievement -Nestling - for killing three times  Mamma Longlegs.

13:03 A whole nest of spiders needs to be exterminated as Mamma Longlegs is on the loose.

Where does this boss spawn?

Answer 1

She spawns South-west of Venore (here).

Here is some extra info about drop loot:

Statistics made after Update 8.6.
Mamma Longlegs, 216 kills.

Sprite	Amount	Item	Times	Total amount	Percentage	Kills to get 1	Average
	1-100	Gold Coin	216	10155	100%	1	47.01
	1-10	Platinum Coin	216	1157	100%	1	5.36
	-	Spider Silk	165	-	76.39%	2	-
	1-4	Great Health Potion	121	286	56.02%	2	1.32
	1	Time Ring	82	82	37.96%	3	0.38
	1	Stealth Ring	68	68	31.48%	4	0.31
	1	Energy Ring	63	63	29.17%	4	0.29
	1	Steel Helmet	28	28	12.96%	8	0.13
	1	Platinum Amulet	19	19	8.8%	12	0.09
	1	Knight Legs	18	18	8.33%	12	0.08
	1	Knight Armor	11	11	5.09%	20	0.05
	1	Spool of Yarn	3	3	1.39%	72	0.01
	-	Bloody Edge	1	-	0.46%	216	-

Comments

Uhhh u went faster than me ahaha gw!

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I got here and you Bibby, so we have a draw  rsrs

Answer 2

You can find  Mamma Longlegs in Venore, exactly here:

But keep in mind that you only can enter 1 time per day, this means that to complete the achivement you have to face the Mamma Longlegs 3 times in 3 diferents days, hope I explain well what i means.