The squad gathered in Brisbane on Monday for their latest training camp ahead of their departure but will travel without captain Lanning, who has withdrawn from the series to remain at home to manage an undisclosed medical issue.
"I've finally probably come to terms with it, it's been a rough couple of days," Healy told ESPNcricinfo. "Everyone is a little bit emotional about the whole Meg situation but at the same time I'm grappling with being really excited and nervous about the challenge of captaining an Ashes series."
Australia head coach Shelley Nitschke could not shed any light on what Lanning was dealing with - although it's understood not to be related to her break from the game last year - but admitted her sudden absence from the tour had rocked the squad as they gathered together for the first time since the announcement was made on Saturday.
"I'm sure they were a little bit rattled by the news," Nitschke said. "But I think Meg is in our thoughts. We also know that she wants us to go over there and get the job done.
"We've had some time to sort of get our head around it now and having the girls up here this week, it's really nice to get them together."
"The fact that she [Healy] captained the team in India last year and did a fantastic job, the girls got around her, played some really good cricket, so I think she should take a lot of confidence out of that and I think she enjoyed it."
Australia women's coach Shelley Nitschke
Australia have dealt with Lanning's absence previously during the successful T20I tour of India late last year when Lanning took a break from the game with Healy standing in as captain and vice-captain Tahlia McGrath taking one game when she was injured. Nitschke believes that Healy and the group will be able to handle Lanning's absence again.
"[Healy] had a big couple of days herself, to find out that she's captaining for an Ashes series," Nitschke said. "But I think the fact that she captained the team in India last year and did a fantastic job, the girls got around her, played some really good cricket, so I think she should take a lot of confidence out of that and I think she enjoyed it.
"I think we've got some really good leaders in the group. We've got a lot of experience in the group. I think one thing that we've been really good at over the years is just being able to adapt and take some knocks as they come. I've got the utmost confidence in our group to head across and hopefully get the job done."
The India tour is an experience Healy is now even more grateful for as she embarks on the pressure and expectation of an Ashes.
"I'm a firm believer that everything happens for a reason and I'm kind of glad that happened over in India, that I was thrown amongst it and got to do it the way we wanted to," she said. "It was new for Shell as well so we were both going there and leaving our mark on the group. Grateful to have that experience and hopefully we can carry on from where that left off and get amongst England."
However, the void Lanning leaves in Australia's top order might not be as easily covered in the Test match, given there are already holes to fill. Lanning and Healy have occupied a spot in the top three in two of the last three Tests Australia have played dating back to the 2019 Ashes. Healy opened in all three games while the recently retired Rachael Haynes opened in Australia's last two Tests. Lanning batted at No. 5 in the last women's Ashes Test in early 2022 in Canberra and made 93 in the first innings, her highest Test score.
"It's a lot on her plate," Nitschke said. "I think it's a definite conversation that we'll be having pretty soon to see how that might look for her in the batting order."
Australia did pair Beth Mooney and Phoebe Litchfield together with great success in the ODI series against Pakistan earlier this year when Healy was injured. Mooney has opened in three of her seven Test innings and batted at No.3 in the last Test against England in 2022 and looks set to replace Haynes, while Litchfield made 78 not out and 67 not out in her first two ODIs opening the batting and is well and truly in the frame to make her Test debut in Nottingham.
"Phoebe is so talented...so she's certainly got the attributes," Nitschke said. "I think when we get over there in the English conditions, we've been training here with red balls and we had some overcast conditions in the first camp, but it's just different again over there.
"I think there's a little bit to play out before we sort of work out who our best XI is for that Test match. But Phoebs is certainly putting her hand up. We'll see where it lands."
Australia, who have been training with the red Dukes ball in Brisbane ahead of the Test, will play a two day intrasquad game this week involving players from the Australia A squad.